WO2011155300A1 - Display panel and liquid crystal display device - Google Patents

Display panel and liquid crystal display device Download PDF

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Publication number
WO2011155300A1
WO2011155300A1 PCT/JP2011/061518 JP2011061518W WO2011155300A1 WO 2011155300 A1 WO2011155300 A1 WO 2011155300A1 JP 2011061518 W JP2011061518 W JP 2011061518W WO 2011155300 A1 WO2011155300 A1 WO 2011155300A1
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pixel
liquid crystal
sub
electrode
value
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PCT/JP2011/061518
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French (fr)
Japanese (ja)
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昇平 勝田
豪 鎌田
井出　哲也
誠二 大橋
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シャープ株式会社
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active matrix
    • G09G3/3659—Control of matrices with row and column drivers using an active matrix the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1343—Electrodes
    • G02F1/134309—Electrodes characterised by their geometrical arrangement
    • G02F1/134345—Subdivided pixels, e.g. for grey scale or redundancy
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/52—RGB geometrical arrangements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0439—Pixel structures
    • G09G2300/0443—Pixel structures with several sub-pixels for the same colour in a pixel, not specifically used to display gradations
    • G09G2300/0447—Pixel structures with several sub-pixels for the same colour in a pixel, not specifically used to display gradations for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0439—Pixel structures
    • G09G2300/0452—Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0814—Several active elements per pixel in active matrix panels used for selection purposes, e.g. logical AND for partial update
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
    • G09G2300/0852—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor being a dynamic memory with more than one capacitor
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/0876—Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0242—Compensation of deficiencies in the appearance of colours

Definitions

  • the present invention relates to a display panel that displays an image using liquid crystal.
  • the present invention relates to a display panel that displays a color image by a combination of three primary colors and a color other than the three primary colors.
  • the present invention also relates to a liquid crystal display device including such a display panel.
  • liquid crystal display devices are widely used in television receivers, personal computer monitor devices, portable liquid crystal terminals, and the like.
  • a liquid crystal display device used for these applications since a user may view a display image from various directions, high viewing angle characteristics are required.
  • Patent Document 1 discloses a voltage applied to a first subpixel electrode connected to a thin film transistor (TFT: Thin Film Transistor) and a second subpixel capacitively coupled to the first subpixel electrode.
  • TFT Thin Film Transistor
  • a liquid crystal display device capable of improving the viewing angle characteristics by making the ratio of the voltage applied to the electrodes different in each sub-pixel.
  • Patent Document 2 for blue / cyan color pixels, the wavelength dispersion of the VA liquid crystal is reduced by reducing the voltage difference between the voltage applied to the first sub-pixel and the voltage applied to the second sub-pixel.
  • a liquid crystal display device that can alleviate the difference in viewing characteristics of each color of RGB due to the above and improve the color shift at an oblique viewing angle.
  • Japanese Patent Publication Japanese Patent Laid-Open No. 2006-48055” (published on February 16, 2006) International Publication Number WO2008 / 018552A1 (published February 14, 2008)
  • Patent Document 1 and Patent Document 2 are used, there is a problem that the effect of suppressing the phenomenon of color misregistration is limited.
  • multi-primary liquid crystal display devices display devices (hereinafter referred to as “multi-primary liquid crystal display devices”) have been developed.
  • the multi-primary color liquid crystal display device can significantly increase the number of colors that can be expressed, as compared with a conventional liquid crystal display device that performs display using only the three primary colors of red, green, and blue.
  • a multi-primary color liquid crystal display device for example, there is a liquid crystal display device that displays a color image by a combination of three primary colors of red, green, and blue and yellow.
  • the inventor has effectively reduced the phenomenon of color misregistration in such a multi-primary type liquid crystal display device by suppressing a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel. It was found that it is possible to suppress it.
  • the present invention has been made on the basis of the above-mentioned knowledge by the inventor in view of the above problems, and its object is to achieve steep luminance at an oblique viewing angle without increasing the number of sub-pixels in each color pixel.
  • An object of the present invention is to realize a multi-primary color type liquid crystal display device capable of effectively suppressing the phenomenon of color misregistration caused by a change.
  • the inventor relates to the above problem, a voltage difference applied to each subpixel electrode included in each of the pixels corresponding to the three primary colors, and a subpixel electrode included in the pixel corresponding to a color other than the three primary colors. It was found that the phenomenon of color misregistration at an oblique viewing angle can be suppressed by making the potential difference between the voltages applied to the two different from each other.
  • the display panel according to the present invention has been made based on the above findings obtained by the inventors.
  • the display panel according to the present invention has three primary colors and a plurality of pixels that individually display a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors, and each of the plurality of pixels.
  • a first potential difference is generated between the sub-pixel electrode of the second sub-pixel and the sub-pixel electrode and the second sub-pixel of the first sub-pixel of the pixel displaying the specific color mixture.
  • the cause different second potential difference between the first potential difference is characterized in that.
  • the sub-pixel electrode and the second sub-pixel in the first sub-pixel of a pixel that respectively displays a plurality of specific primary colors among the three primary colors.
  • a first sub-pixel for a pixel that generates a first potential difference with the sub-pixel electrode in the pixel and displays a specific mixed color obtained by combining the plurality of specific primary colors among the three primary colors.
  • a second potential difference different from the first potential difference is generated between the sub-pixel electrode in the pixel and the sub-pixel electrode in the second sub-pixel.
  • the display panel configured as described above has an oblique viewing angle with respect to an image displayed using a plurality of specific primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors.
  • the display panel according to the present invention includes a plurality of pixels that individually display three primary colors and a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors;
  • Each of the pixels includes a first subpixel and a second subpixel, and each of the first subpixel and the second subpixel is opposed to the counter electrode through a liquid crystal layer.
  • the second Between the subpixel electrodes in sub-pixels, giving rise to different second potential difference between the first potential difference, it is characterized in that.
  • the display panel configured as described above, it is possible to effectively suppress the phenomenon of color shift caused by a steep luminance change at an oblique viewing angle without increasing the number of subpixels in each color pixel. it can.
  • FIG. 2 is a timing chart schematically showing waveforms and timings of respective voltages when driving the liquid crystal display device according to the first embodiment of the present invention, wherein (a) is a data signal supplied from a source driver to a source bus line; (B) shows the voltage waveform of the auxiliary capacitor drive signal supplied to the n th CS bus line by the CS driver, and (c) shows the n + 1 th CS bus line by the CS driver. (D) shows the voltage waveform of the gate signal supplied to the gate bus line by the gate driver, and (e) shows the voltage waveform of the pixel displaying red.
  • the voltage waveform of the subpixel electrode of the bright pixel provided is shown, and (f) shows the voltage waveform of the subpixel electrode of the dark pixel provided in the pixel displaying red.
  • it is a figure which shows the gradation -XYZ value characteristic in a front viewing angle of the liquid crystal display device which concerns on a comparative example.
  • it is a figure which shows the gradation -XYZ value characteristic in the polar angle of 60 degree
  • the 1st Embodiment of this invention it is a figure which shows the gradation-local-gamma characteristic in the polar angle of 60 degree
  • FIG. 1 shows the equivalent circuit of the display panel with which the liquid crystal display device which concerns on the 2nd Embodiment of this invention is provided. It is a timing chart which shows typically the waveform and timing of each voltage at the time of driving the liquid crystal display concerning a 2nd embodiment of the present invention, and (a) is a data signal which a source driver supplies to a source bus line (B) shows the voltage waveform of the gate signal supplied by the gate driver to the l-th gate bus line, and (c) shows the voltage waveform of the gate driver supplied to the l + 1-th gate bus line.
  • the voltage waveform of the gate signal to be supplied is shown, (d) shows the voltage waveform of the sub-pixel electrode of the bright pixel included in the pixel displaying red, and (e) is included in the pixel displaying red.
  • the voltage waveform of the subpixel electrode of a dark pixel is shown.
  • it is a figure which shows the gradation -XYZ value characteristic in a front viewing angle of the liquid crystal display device which concerns on a comparative example.
  • the 2nd Embodiment of this invention it is a figure which shows the gradation-local-gamma characteristic in the polar angle of 60 degree
  • the optimum storage capacitor ratio for improving the viewing angle characteristic is described, and (a) shows the storage capacitor in the green pixel of the storage capacitor in the yellow pixel. And (b) is a graph showing the relationship between the ratio and the standard deviation ⁇ , and the relationship between the ratio and the standard deviation ⁇ in the halftone of the local ⁇ of the Y value corresponding to each ratio. .
  • Embodiment 1 A first embodiment according to the present invention will be described below with reference to FIGS.
  • a vertical alignment type liquid crystal display device VA mode liquid crystal display device
  • a liquid crystal material having a negative dielectric anisotropy in which the effect of the present invention appears remarkably, will be described.
  • the present invention can be applied to a TN mode liquid crystal display device.
  • FIG. 1 is a diagram showing an equivalent circuit of a pixel having a multi-pixel structure in a display panel included in the liquid crystal display device 1 according to the present embodiment.
  • the liquid crystal display device 1 includes a plurality of gate bus lines 2, a plurality of source bus lines 4, a plurality of switching elements TFT1, a plurality of switching elements TFT2, a plurality of auxiliary capacitors Cs1, and a plurality of display buses.
  • the auxiliary capacitor Cs2 and a plurality of CS bus lines 6 are provided.
  • a plurality of pixels are formed on the display panel of the liquid crystal display device 1, and the liquid crystal display device 1 drives each pixel by a multi-pixel drive method.
  • Each pixel has a liquid crystal layer and an electrode for applying a voltage to the liquid crystal layer, and is arranged in a matrix having rows and columns.
  • the gate bus line 2 l indicates the l-th gate bus line 2 (where l is a positive integer).
  • the source bus line 4m indicates the m-th source bus line 4m (where m is a positive integer).
  • the CS bus line 6n indicates the nth (where n is a positive integer) CS bus line 6.
  • the liquid crystal display device 1 includes a gate driver that supplies a gate signal to each gate bus line 2, a source driver that supplies a data signal to each source bus line 4, and an auxiliary to each CS bus line 6.
  • a CS driver that supplies a capacitive drive signal is connected to each other. Each of these drivers operates based on a control signal output from a control circuit (not shown).
  • the plurality of gate bus lines 2 and the plurality of source bus lines 4 are formed so as to intersect each other via an insulating film (not shown).
  • one pixel is formed for each region defined by one gate bus line 2 and one source bus line 4.
  • the pixel individually displays one of a plurality of different types of colors.
  • the plurality of different types of colors include a plurality of primary colors and at least one or more colors obtained by combining at least two primary colors among the plurality of primary colors.
  • the plurality of different types of colors include red, green, and blue as the three primary colors of light (hereinafter simply referred to as “three primary colors”), and at least two of the plurality of primary colors A case where yellow (a combination of red and green) is included as a color obtained by combining primary colors will be described.
  • an R pixel 8 for displaying red, a G pixel 10 for displaying green, a B pixel 12 for displaying blue, and a Ye pixel 14 for displaying yellow are formed. By using these pixels in combination, a desired color image is displayed.
  • the liquid crystal display device 1 displays the three primary colors by including pixels that display not only the three primary colors of red, green, and blue, but also yellow that is a color other than the three primary colors.
  • the number of colors that can be expressed by the color mixture of colors displayed by each pixel can be significantly increased.
  • the subjective beauty of colors such as light blue, yellow, and gold can be significantly improved.
  • Each of the R pixel 8, the G pixel 10, the B pixel 12, and the Ye pixel 14 has two sub-pixels (bright pixel and dark pixel) that can apply different voltages to the liquid crystal layer. Yes.
  • the R pixel 8 has a bright pixel 8a and a dark pixel 8b
  • the G pixel 10 has a bright pixel 10a and a dark pixel 10b
  • the B pixel 12 has a bright pixel 12a and a dark pixel 12b
  • the Ye pixel 14 has a bright pixel. It has a pixel 14a and a dark pixel 14b.
  • Each sub-pixel has a liquid crystal capacitance formed by a counter electrode and a sub-pixel electrode facing the counter electrode via a liquid crystal layer. Further, there is at least one auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the subpixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode through the insulating layer. is doing.
  • the liquid crystal capacitor of the bright pixel is supplied via at least one auxiliary capacitor corresponding thereto.
  • the applied voltage is supplied via at least one auxiliary capacitor corresponding thereto.
  • a sub-pixel included in each pixel has a liquid crystal capacitance.
  • the bright pixel has a liquid crystal capacitance Clc1
  • the dark pixel has a liquid crystal capacitance Clc2.
  • the bright pixel 8a of the R pixel 8 has a liquid crystal capacitance Clc1R
  • the dark pixel 8b has a liquid crystal capacitance Clc2R
  • the bright pixel 10a of the G pixel 10 has a liquid crystal capacitance Clc1G
  • the dark pixel 10b has a liquid crystal capacitance Clc2G
  • the bright pixel 12a of the B pixel 12 has a liquid crystal capacitance Clc1B.
  • the dark pixel 12b has a liquid crystal capacitance Clc2B
  • the bright pixel 14a of the Ye pixel 14 has a liquid crystal capacitance Clc1Ye
  • the dark pixel 14b has a liquid crystal capacitance Clc2Ye.
  • the first auxiliary capacitor Cs1 is electrically connected in parallel to the liquid crystal capacitor Clc1, and the second auxiliary capacitor Cs2 is electrically connected in parallel to the liquid crystal capacitor Clc2.
  • an auxiliary capacitor Cs1R is electrically connected in parallel to the liquid crystal capacitor Clc1R
  • an auxiliary capacitor Cs2R is electrically connected in parallel to the liquid crystal capacitor Clc2R
  • the auxiliary capacitor Cs1G is electrically connected in parallel to the liquid crystal capacitor Clc1G
  • the auxiliary capacitor Cs2G is electrically connected in parallel to the liquid crystal capacitor Clc2G
  • the liquid crystal capacitor Clc1B is electrically connected to the liquid crystal capacitor Clc1B.
  • the auxiliary capacitor Cs1B is connected in parallel, the auxiliary capacitor Cs2B is electrically connected in parallel to the liquid crystal capacitor Clc2B, the auxiliary capacitor Cs1Ye is electrically connected in parallel to the liquid crystal capacitor Clc1Ye, and the liquid crystal capacitor Clc2Ye is connected.
  • the auxiliary capacitor Cs1B is connected in parallel, the auxiliary capacitor Cs2B is electrically connected in parallel to the liquid crystal capacitor Clc2B, the auxiliary capacitor Cs1Ye is electrically connected in parallel to the liquid crystal capacitor Clc1Ye, and the liquid crystal capacitor Clc2Ye is connected.
  • auxiliary capacitor CsR when the capacitance value of the auxiliary capacitor Cs1R and the capacitance value of the auxiliary capacitor Cs2R are equal, both are referred to as the auxiliary capacitor CsR, and when the capacitance value of the auxiliary capacitor Cs1G and the capacitance value of the auxiliary capacitor Cs2G are equal.
  • auxiliary capacity CsG when the capacity value of the auxiliary capacity Cs1B and the capacity value of the auxiliary capacity Cs2B are equal, both are referred to as an auxiliary capacity CsB, and the capacity value of the auxiliary capacity Cs1Ye and the auxiliary capacity Cs2Ye Are equal to each other, they are both referred to as an auxiliary capacitor CsYe.
  • TFT1 and TFT2 are formed, respectively.
  • TFT1 is formed in a bright pixel
  • TFT2 is formed in a dark pixel.
  • the auxiliary capacitance electrode of each auxiliary capacitance Cs is connected to the corresponding drain electrode of TFT1 or TFT2.
  • the gate electrodes of TFT1 and TFT2 are connected to a common gate bus line 21, and the source electrodes of TFT1 and TFT2 are connected to a common source bus line 4. That is, as shown in FIG. 1, the source electrodes of the TFT 1R and TFT 2R of the R pixel 8 are connected to the source bus line 4m.
  • the source electrodes of the TFT 1G and TFT 2G of the G pixel 10 are connected to the source bus line 4 (m + 1), and the source electrodes of the TFT 1B and TFT 2B of the B pixel 12 are connected to the source bus line 4 (m + 2).
  • the source electrodes of the TFT1Ye and TFT2Ye of the Ye pixel 14 are connected to the source bus line 4 (m + 3).
  • Each of TFT1 and TFT2 is in a conductive state (on state) when a high level gate signal is applied to its own gate electrode, and when a low level gate signal is applied to its own gate electrode. , It becomes a non-conduction state (off state, cutoff state).
  • a CS bus line 6 extends in parallel to the gate bus line 2 so as to cross a pixel region defined by the gate bus line 2 and the source bus line 4.
  • Each CS bus line 6 is provided in common to the R pixel 8, the G pixel 10, the B pixel 12, and the Ye pixel 14 formed in the same row in the liquid crystal display device 1.
  • the CS bus line 6n is connected to the auxiliary capacitor Cs1R, the auxiliary capacitor Cs1G, the auxiliary capacitor Cs1B, and the auxiliary capacitor Cs1Ye.
  • the CS bus line 6 (n + 1) is connected to the auxiliary capacitor Cs2R, the auxiliary capacitor Cs2G, the auxiliary capacitor Cs2B, and the auxiliary capacitor Cs2Ye.
  • each auxiliary capacitance and the value of each liquid crystal capacitance have a dependency on the voltage applied to each, but are not essential matters in the present embodiment. So ignore such dependencies. However, this premise does not limit the present embodiment, and can be similarly applied to a case where there is such dependency.
  • FIG. 2 is a timing chart schematically showing the waveform and timing of each voltage when the liquid crystal display device 1 is driven.
  • FIG. 2A shows a voltage waveform Vs of a data signal supplied from the source driver to the source bus line 4, and FIG. 2B shows an auxiliary capacitor drive signal supplied from the CS driver to the CS bus line 6n.
  • FIG. 2C shows a voltage waveform (that is, the voltage waveform of the CS bus line 6n) Vcs1, and FIG. 2C shows a voltage waveform of the auxiliary capacitance drive signal (that is, the CS bus) that the CS driver supplies to the CS bus line 6 (n + 1).
  • 2 (d) shows the voltage waveform Vg of the gate signal supplied to the gate bus line 2 by the gate driver, and FIG. 2 (e) shows the voltage waveform Vg of the line 6 (n + 1).
  • FIG. 2F shows the voltage waveform Vlc2R of the subpixel electrode of the dark pixel 8b included in the R pixel 8. That. Moreover, the broken line in the figure indicates the voltage waveform COMMON (Vcom) of the counter electrode.
  • the voltage Vg of the gate signal changes from VgL (low) to VgH (high), so that TFT1 and TFT2 are simultaneously turned on (on state). Accordingly, the voltage of the data signal is applied to the sub-pixel electrode of the bright pixel 8a and the sub-pixel electrode of the dark pixel 8b via the source bus line 4, and the sub-pixel electrode of the bright pixel 8a and the dark pixel 8b Any voltage of the sub-pixel electrode of the pixel 8b changes to the voltage Vs of the data signal.
  • the voltage of the data signal is also applied to the auxiliary capacitor Cs1R of the bright pixel 8a and the auxiliary capacitor Cs2R of the dark pixel 8b via the source bus line 4, and the auxiliary capacitor electrode of the bright pixel 8a and the dark capacitor 8s Any voltage of the auxiliary capacitance electrode of the pixel 8b changes to the voltage Vs of the data signal.
  • the voltage Vs of the data signal transmitted via the source bus line 4 is a display voltage corresponding to the gradation to be displayed in the pixel, and the TFT is in an on state (sometimes referred to as “selection period”). , The corresponding pixel is written.
  • the voltage Vg of the gate signal changes from VgH to VgL, so that TFT1 and TFT2 are simultaneously turned off (off state). Accordingly, the sub-pixel electrode of the bright pixel 8a, the sub-pixel electrode of the dark pixel 8b, the auxiliary capacitance electrode of the bright pixel 8a, and the auxiliary capacitance electrode of the dark pixel 8b are all electrically insulated from the source bus line 4. (The period in this state may be referred to as “non-selection period”.)
  • Vlc1R Vs ⁇ Vd (1a)
  • Vlc2R Vs ⁇ Vd (1b) It becomes.
  • Vcs2 Vcom + (1/2) Vad (2b) It is.
  • the waveforms of the voltages Vcs1 and Vcs2 of the auxiliary capacitance drive signal supplied to the CS bus line 6 exemplified here are Vad with a total width of Vad and phases opposite to each other (180 ° different) (with a duty ratio of 1). : 1).
  • the voltage Vcs1 of the CS bus line 6n connected to the auxiliary capacitor Cs1 changes from Vcom ⁇ (1/2) Vad to Vcom + (1/2) Vad
  • the CS connected to the auxiliary capacitor Cs2 The voltage Vcs2 of the bus line 6 (n + 1) changes from Vcom + (1/2) Vad to Vcom ⁇ (1/2) Vad.
  • Vlc2R Vs ⁇ Vd ⁇ K2R ⁇ Vad (3b) To change.
  • Vcs1 changes from Vcom + (1/2) Vad to Vcom- (1/2) Vad
  • Vcs2 changes from Vcom- (1/2) Vad to Vcom + (1/2) Vad
  • Vlc1R also changes from the values represented by the equations (3a) and (3b) to the values represented by the equations (1a) and (1b), respectively.
  • Vcs1 changes from Vcom ⁇ (1/2) Vad to Vcom + (1/2) Vad
  • Vcs2 changes from Vcom + (1/2) Vad to Vcom ⁇ (1/2) Vad
  • Vlc1R also changes from the values represented by the mathematical expressions (1a) and (1b) to the values represented by the mathematical expressions (3a) and (3b), respectively.
  • V1R Vlc1R-Vcom (6a)
  • V2R Vs ⁇ Vd ⁇ K2R ⁇ (1/2) Vad ⁇ Vcom (7b) It becomes.
  • K1R and K2R are represented by mathematical formulas (4a) and (4b), respectively.
  • DR represents the ratio of the auxiliary capacitance to the liquid crystal capacitance in each sub-pixel of the R pixel
  • KR DR / (DR + 1).
  • the ratio of the auxiliary capacity to the liquid crystal capacity in the bright pixel and the ratio of the auxiliary capacity to the liquid crystal capacity in the dark pixel (hereinafter also referred to as “capacitance ratio”) are equal to each other,
  • the difference in effective voltage applied to each liquid crystal layer of each pixel can be characterized by the capacitance ratio.
  • the G pixel 10 is also driven in the same manner, and the difference ⁇ V12G (referred to as “ ⁇ V ⁇ ” relating to the G pixel) between the effective voltages applied to the liquid crystal layers of the bright pixel 10a and the dark pixel 10b included in the G pixel 10.
  • ⁇ V12G (1/2) ⁇ (K1G + K2G) ⁇ Vad (10) It is expressed.
  • ⁇ V12G KG ⁇ Vad (10 ′) It is expressed.
  • KG DG / (DG + 1)
  • the B pixel 12 is also driven in the same manner, and the difference ⁇ V12B in effective voltage applied to the liquid crystal layer of each of the bright pixel 12a and the dark pixel 12b included in the B pixel 12 (“ ⁇ V ⁇ relating to the B pixel”). ”).
  • ⁇ V12B (1/2) ⁇ (K1B + K2B) ⁇ Vad (13) It is expressed.
  • K2B Cs2B / (Clc2B + Cs2B) (14b) It is.
  • ⁇ V12B KB ⁇ Vad (13 ′) It is expressed.
  • KB DB / (DB + 1)
  • the Ye pixel 14 is also driven in the same manner, and the difference between the effective voltages applied to the liquid crystal layers of the bright pixel 14a and the dark pixel 14b included in the Ye pixel 14 ⁇ V12Ye (“ ⁇ V ⁇ relating to the Ye pixel”). ”).
  • ⁇ V12Ye (1/2) ⁇ (K1Ye + K2Ye) ⁇ Vad (16) It is expressed.
  • K2Ye Cs2Ye / (Clc2Ye + Cs2Ye) (17b) It is.
  • ⁇ V12Ye KYe ⁇ Vad (16 ′) It is expressed.
  • KYe DYe / (DYe + 1)
  • the difference in effective voltage applied to each liquid crystal layer of the subpixel included in each pixel is set to a desired value.
  • the difference in effective voltage applied to the respective liquid crystal layers of the sub-pixels included in the pixel can be changed by appropriately changing the value of the capacitance ratio. Can be set to a value.
  • the values of the liquid crystal capacitance and the auxiliary capacitance in each subpixel included in each pixel, or the capacitance ratio in each pixel can be determined so as to reduce the phenomenon of color misregistration that may occur in the display image.
  • the phenomenon of color misregistration is a phenomenon in which the color tone of a display image looks different when observed obliquely compared to when the display screen is observed from the front.
  • RGB color system a color system that is a system for quantitatively expressing colors
  • RGB color system using three primary colors of red (R), green (G), and blue (B).
  • R red
  • G green
  • B blue
  • RGB color system not all perceptible colors can be expressed completely, and a single wavelength color found in, for example, laser light is outside the RGB color system. If a negative value is permitted for the coefficient of the RGB value, an arbitrary color can be represented even in the RGB color system, but inconvenience arises in handling. In general, therefore, an XYZ color system in which the RGB color system is improved is used.
  • a desired color is represented by a combination of tristimulus values (X value, Y value, Z value).
  • X values, Y values, and Z values that are new stimulus values are obtained by adding the original R value, G value, and B value to each other.
  • Y value corresponds to brightness stimulus. That is, the Y value can be used as a representative value of brightness.
  • the X value is a stimulus value mainly representing red, but also contains a certain amount of color stimulus in the blue wavelength region.
  • the Z value is a color stimulus mainly representing blue.
  • colors expressed by a mixed color of red, green, blue, and yellow displayed by each pixel can also be expressed using the XYZ color system.
  • the yellow component displayed by the Ye pixel 14 mainly contributes to the X value and the Y value in the XYZ color system.
  • FIG. 3 is a diagram illustrating a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device according to the comparative example.
  • the liquid crystal display device according to the comparative example is a VA mode liquid crystal display device, and has the same pixel structure as the liquid crystal display device 1 according to the present embodiment.
  • the capacitance ratios of the sub-pixels included in each of the R pixel 8, the G pixel 10, and the Ye pixel 14 in the liquid crystal display device according to the comparative example are set to be equal to each other.
  • the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant ⁇ (gamma) value. Therefore, when the display screen of the liquid crystal display device according to the comparative example is observed from the front, the phenomenon of color misregistration does not occur.
  • the VA mode liquid crystal display device uses the birefringence effect of the liquid crystal layer and the retardation of the liquid crystal layer has wavelength dispersion, the transmittance varies depending on the wavelength of light.
  • the retardation of the liquid crystal layer is apparently larger at an oblique viewing angle than at the front viewing angle, the dependence of the transmittance variation on the light wavelength is greater than the front viewing angle at the oblique viewing angle.
  • the ⁇ value (more specifically, the value of local ⁇ described later) when the screen is observed from the oblique direction is not constant. The phenomenon occurs. Further, the color shift phenomenon does not occur only in the VA mode liquid crystal display device, but also occurs in, for example, the TN mode liquid crystal display device.
  • FIG. 4 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device according to the comparative example.
  • the X value and the Y value rise at substantially the same gradation (approximately 110 gradations) in the halftone. That is, at the polar angle of 60 degrees, the slopes of the graphs indicating the X value and the Y value both change at about 110 gradations, and are about 110 gradations or more and about 150 than the inclinations at about 110 gradations or less. The slope below the gradation is larger.
  • both the graph showing the X value and the graph showing the Y value have turned from the vicinity of 120 to 130 gradations to a gentle slope.
  • Such a profile of the graph showing the X value and the Y value shows that the ⁇ value for each of the X value and the Y value varies greatly, particularly in the range of about 100 gradations to about 150 gradations. Yes.
  • FIG. 5 is a diagram showing the gradation-local ⁇ characteristics at a polar angle of 60 degrees of the liquid crystal display device according to the comparative example.
  • local ⁇ is an index indicating a local gradient of the ⁇ value.
  • T is the maximum luminance in the optical characteristics measured from a predetermined angle with respect to the normal direction of the display screen
  • ta is the luminance based on the gradation value a from the same direction as the predetermined angle.
  • the local ⁇ value related to the X value and the local ⁇ value related to the Y value are substantially equal to each other at about 100 gradations or less, and both show steep rises at about 100 gradations.
  • the local ⁇ related to the X value increases by about 0.9 in the section from about 100 gradations to about 120 gradations, and the local ⁇ related to the Y value is about 1. in the section from about 100 gradations to about 120 gradations. 1 increase.
  • the value of local ⁇ is desirably constant even at an oblique viewing angle. This is because the value of local ⁇ is adjusted to be constant at the front viewing angle.
  • the local ⁇ value related to the X value and the local ⁇ value related to the Y value are particularly in the range from about 100 to about 150 gradations. It has changed greatly.
  • the standard deviation ⁇ of local ⁇ can be used as an index indicating the magnitude of color shift.
  • a large standard deviation ⁇ corresponds to a large change in local ⁇ for each gradation
  • a small standard deviation ⁇ means a small change in local ⁇ for each gradation, that is, local ⁇ is constant. This is to cope with closeness. Therefore, for example, if the value of the auxiliary capacitance and the liquid crystal capacitance in each pixel or the capacitance ratio in each pixel can be optimized so that the value of the standard deviation ⁇ of the local ⁇ becomes smaller, the phenomenon of color shift can be reduced. Can be reduced.
  • the capacitance ratio DYe is smaller than the capacitance ratio DR and the capacitance ratio DG
  • the difference ⁇ V12Ye between the effective voltages applied to the liquid crystal layers of the sub-pixels included in the Ye pixel 14 is the R pixel 8 and G It is smaller than the difference ⁇ V12R and ⁇ V12G in effective voltage applied to the liquid crystal layer of each subpixel included in each pixel 10.
  • the bright pixel 8a included in the R pixel 8 the bright pixel 10a included in the G pixel 10
  • the bright pixel 14a included in the Ye pixel 14 mainly contributes, and as the gradation increases, the dark pixel 14b included in the Ye pixel 14 starts to contribute, and as the gradation further increases, the dark pixel 8b included in the R pixel 8.
  • the dark pixel 10b included in the G pixel 10 starts to contribute.
  • the luminance of the color including red, green, and yellow as components rises in at least three stages as the gradation increases.
  • the liquid crystal display device 1 according to the present embodiment displays colors including red, green, and yellow as components, the same effect as that in which the pixel is divided into at least three sub-pixels is obtained. Is shown. Therefore, in the liquid crystal display device 1 according to the present embodiment, the local ⁇ particularly with respect to the X value and the Y value can be made more constant.
  • the effective voltage difference ⁇ V12Ye in the Ye pixel 14 is equal to the effective voltage difference ⁇ V12R in the R pixel 8 and the G pixel 10, respectively. Equal to ⁇ V12G.
  • the bright pixel 8a included in the R pixel 8 the bright pixel 10a included in the G pixel 10
  • the bright pixel 14a included in the Ye pixel 14 mainly contribute.
  • the dark pixel 14b included in the Ye pixel 14 the dark pixel 8b included in the R pixel 8
  • the dark pixel 10b included in the G pixel 10 start to contribute uniformly. Therefore, in the liquid crystal display device according to the comparative example, the luminance of the color including red, green, and yellow as components only rises in two stages.
  • the liquid crystal display device 1 sets the capacitance ratio DYe to be smaller than the capacitance ratio DR and the capacitance ratio DG, so that the luminance of the color including red, green, and yellow as components is set. Can be raised in at least three stages as the gray level increases, so that the local ⁇ particularly for the X value and the Y value can be made closer to constant as compared with the liquid crystal display device according to the comparative example. . Therefore, the liquid crystal display device 1 can effectively suppress the phenomenon of color misregistration at an oblique viewing angle.
  • FIG. 6 is a diagram showing a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device 1 according to the present embodiment.
  • the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant ⁇ (gamma) value. Therefore, when the display screen of the liquid crystal display device 1 according to the present embodiment is observed from the front, the phenomenon of color misregistration does not occur.
  • FIG. 7 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device 1 according to the present embodiment.
  • the change in the ⁇ value in the range of approximately 100 gradations to approximately 150 gradations is smaller than that of the liquid crystal display device according to the comparative example.
  • the curve of the graph showing the X value and the Y value is closer to the ideal curve having a constant ⁇ value, so that the phenomenon of color shift is suppressed.
  • FIG. 8 is a diagram showing the gradation-local ⁇ characteristic at the polar angle of 60 degrees of the liquid crystal display device 1 according to the present embodiment.
  • the value of local ⁇ related to the X value and the value of local ⁇ related to the Y value take substantially constant values in a range from about 20 gradations to about 220 gradations. This is in contrast to the fact that the value of local ⁇ relating to the X value and the value of local ⁇ relating to the Y value in the liquid crystal display device according to the comparative example change greatly in the range of approximately 100 gradations to approximately 150 gradations. It is.
  • the effective voltage difference ⁇ V12Ye in the Ye pixel 14 is smaller than the effective voltage differences ⁇ V12R and ⁇ V12G in the R pixel 8 and the G pixel 10, respectively. By doing so, the phenomenon of color misregistration at an oblique viewing angle can be effectively suppressed.
  • FIG. 9A shows the ratio of the auxiliary capacitance CsYe to the auxiliary capacitance CsG set experimentally when the liquid crystal capacitances in the sub-pixels are set to be equal to each other in the liquid crystal display device 1 according to the present embodiment. It is a table
  • FIG. 9B is a graph showing the relationship between the ratio CsYe / CsG and the standard deviation ⁇ .
  • the liquid crystal display device 1 according to the present embodiment can be expressed as an optimized liquid crystal display device so that each auxiliary capacitor can most effectively suppress the phenomenon of color misregistration. .
  • VA mode liquid crystal display device using a liquid crystal material having a negative dielectric anisotropy, in which the effect of the present invention appears remarkably, will be described.
  • the present invention can be applied to a TN mode liquid crystal display device.
  • FIG. 10 is a diagram showing an equivalent circuit of a pixel in the liquid crystal display device 100 according to the present embodiment, which is driven by the 3 TFT driving method.
  • the liquid crystal display device 100 may be referred to as a plurality of gate bus lines 2 ′, a plurality of source bus lines 4 ′, and a plurality of CS bus lines 6 ′ (auxiliary capacitor lines or storage capacitor bus lines).
  • a plurality of pixels are formed in the liquid crystal display device 100, and each pixel is driven by a 3TFT driving method.
  • Each pixel has a liquid crystal layer and an electrode for applying a voltage to the liquid crystal layer, and is arranged in a matrix having rows and columns.
  • a gate bus line 2l ' indicates l (where l is a positive integer) first gate bus line 2'.
  • the source bus line 4m ′ indicates the m-th source bus line 4 ′ (where m is a positive integer).
  • the CS bus line 6n ' indicates the nth (where n is a positive integer) CS bus line 6'.
  • the liquid crystal display device 100 includes a gate driver that supplies a scanning signal to each gate bus line 2 ′, a source driver that supplies a data signal to each source bus line 4 ′, and each CS bus line 6.
  • a CS driver for supplying a storage capacitor drive signal to each other is connected. Each of these drivers operates based on a control signal output from a control circuit (not shown).
  • the plurality of gate bus lines 2 ′ and the plurality of source bus lines 4 ′ are formed so as to intersect with each other via an insulating film (not shown).
  • one pixel is formed for each region defined by one gate bus line 2 ′ and one source bus line 4 ′.
  • the pixel individually displays one of a plurality of different types of colors.
  • the plurality of different types of colors include a plurality of primary colors and at least one or more colors obtained by combining at least two primary colors among the plurality of primary colors.
  • the plurality of different types of colors include red, green, and blue as the three primary colors of light (hereinafter simply referred to as “three primary colors”), and at least two of the plurality of primary colors A case where yellow (a combination of red and green) is included as a color obtained by combining primary colors will be described.
  • an R pixel 8 ′ for displaying red, a G pixel 10 ′ for displaying green, a B pixel 12 ′ for displaying blue, and a Ye pixel 14 ′ for displaying yellow are formed. Yes.
  • a desired color image is displayed.
  • the liquid crystal display device 100 includes not only pixels that display the three primary colors of red, green, and blue, but also pixels that display yellow, which is a color other than the three primary colors, according to the first embodiment. Similar to the liquid crystal display device 1, the number of colors that can be expressed by the color mixture of colors displayed by the respective pixels can be remarkably increased as compared with the configuration including only the pixels that display the three primary colors. In addition, the subjective beauty of colors such as light blue, yellow, and gold can be significantly improved.
  • Each of the R pixel 8 ', the G pixel 10', the B pixel 12 ', and the Ye pixel 14' has two sub-pixels (bright pixel and dark pixel) that can apply different voltages to the liquid crystal layer. have.
  • the R pixel 8 ′ has a bright pixel 8a ′ and a dark pixel 8b ′
  • the G pixel 10 ′ has a bright pixel 10a ′ and a dark pixel 10b ′
  • the B pixel 12 ′ has a bright pixel 12a ′ and a dark pixel 12b ′
  • the Ye pixel 14 ' has a bright pixel 14a' and a dark pixel 14b '.
  • Each sub-pixel has a liquid crystal capacitance formed by a counter electrode and a sub-pixel electrode facing the counter electrode via a liquid crystal layer. Further, it also has an auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the subpixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode through the insulating layer.
  • Each dark pixel also has a storage capacitor with one end connected to the CS bus line 6 '.
  • a sub-pixel included in each pixel has a liquid crystal capacitance.
  • the bright pixel has a liquid crystal capacitance Clc1 ′, and the dark pixel has a liquid crystal capacitance Clc2 ′.
  • the bright pixel 8a 'of the R pixel 8' has a liquid crystal capacitance Clc1R '
  • the dark pixel 8b' has a liquid crystal capacitance Clc2R '
  • the bright pixel 10a ′ of the G pixel 10 ′ has a liquid crystal capacitor Clc1G ′
  • the dark pixel 10b ′ has a liquid crystal capacitor Clc2G ′
  • the bright pixel 12a ′ of the B pixel 12 ′ is
  • the dark pixel 12b ′ has the liquid crystal capacitor Clc2B ′
  • the bright pixel 14a ′ of the Ye pixel 14 ′ has the liquid crystal capacitor Clc1Ye ′
  • the dark pixel 14b ′ has a liquid crystal capacitance Clc2Ye ′.
  • the first auxiliary capacitor Cs1 ′ is electrically connected in parallel to the liquid crystal capacitor Clc1 ′, and the second auxiliary capacitor Cs2 ′ is electrically connected in parallel to the liquid crystal capacitor Clc2 ′. Yes.
  • an auxiliary capacitor Cs1R ' is electrically connected in parallel to the liquid crystal capacitor Clc1R'
  • an auxiliary capacitor Cs2R ' is electrically connected in parallel to the liquid crystal capacitor Clc2R'.
  • an auxiliary capacitor Cs1G ′ is electrically connected in parallel to the liquid crystal capacitor Clc1G ′
  • an auxiliary capacitor Cs2G ′ is electrically connected in parallel to the liquid crystal capacitor Clc2G ′, and is connected to the liquid crystal capacitor Clc1B ′.
  • the liquid crystal capacitor Clc2B ′ is electrically connected in parallel to the auxiliary capacitor Cs2B ′, and the liquid crystal capacitor Clc1Ye ′ is electrically connected in parallel.
  • a capacitor Cs1Ye ′ is connected, and an auxiliary capacitor Cs2Ye ′ is electrically connected in parallel to the liquid crystal capacitor Clc2Ye ′.
  • Each dark pixel has a storage capacitor Cd ′. More specifically, as shown in FIG. 10, the dark pixel 8b ′ of the R pixel 8 ′ has a storage capacitor CdR ′, and the dark pixel 10b ′ of the G pixel 10 ′ has a storage capacitor CdG ′. The dark pixel 12b ′ of the B pixel 12 ′ has a storage capacitor CdB ′, and the dark pixel 14b ′ of the Ye pixel 14 ′ has a storage capacitor CdYe ′.
  • Each storage capacitor Cd ' is formed by a storage capacitor electrode connected to the source electrode of the corresponding TFT 3', an insulating film, and a storage capacitor counter electrode facing the storage capacitor electrode through the insulating film.
  • Each storage capacitor counter electrode is connected to a CS bus line 6n '.
  • switching elements TFT1 ′ and TFT2 ′ In each of the R pixel 8 ′, the G pixel 10 ′, the B pixel 12 ′, and the Ye pixel 14 ′, a TFT (thin film transistor) 1 ′ and a TFT 2 ′ are formed.
  • the auxiliary capacitance electrode of each auxiliary capacitance Cs ′ is connected to the drain electrode of the corresponding TFT 1 ′ or TFT 2 ′.
  • the gate electrodes of TFT1 'and TFT2' are connected to a common gate bus line 21 ', and the source electrodes of TFT1' and TFT2 'are connected to a common source bus line 4'. That is, as shown in FIG.
  • the source electrodes of the TFT 1R ′ and TFT 2R ′ of the R pixel 8 ′ are connected to the source bus line 4m ′.
  • the source electrodes of TFT 1G ′ and TFT 2G ′ of the G pixel 10 are connected to the source bus line 4 (m + 1) ′
  • the source electrodes of TFT 1B ′ and TFT 2B ′ of the B pixel 12 ′ are connected to the source bus line 4
  • the source electrodes of the TFT 1Ye ′ and the TFT 2Ye ′ of the Ye pixel 14 ′ are connected to the source bus line 4 (m + 3) ′.
  • Each of the TFT 1 ′, TFT 2 ′, and TFT 3 ′ described later is in a conductive state (on state) when a high level gate signal is applied to its own gate electrode, and the low level is applied to its own gate electrode.
  • the gate signal is applied, the non-conduction state (off state, cutoff state) is established.
  • the R pixel 8 ′, the G pixel 10 ′, the B pixel 12 ′, and the Ye pixel 14 ′ are each formed with a corresponding TFT 3 ′.
  • the gate electrode of the TFT 3 ′ is electrically connected to the next gate bus line of the pixel, that is, the gate bus line 2 (l + 1) ′.
  • the drain electrode of each TFT 3 ′ is electrically connected to the pixel electrodes of the dark pixels 8b ′, 10b ′, 12b ′, and 14b ′ via contact holes.
  • the source electrode of each TFT 3 ′ is connected to the storage capacitor electrode of the corresponding storage capacitor Cd ′.
  • the time difference occurs.
  • the next gate bus line 2 (l + 1) ′ is selected and the TFT 3 ′ is turned on, charge redistribution occurs, and the liquid crystal capacitance Clc1 ′ of each bright pixel and the liquid crystal capacitance Clc2 ′ of each dark pixel are between. This causes a voltage difference.
  • bright pixels 8a ', 10a', 12a ', 14a' and dark pixels 8b ', 10b', 12b ', 14b' are formed in each pixel.
  • a CS bus line 6 ′ extends in parallel with the gate bus line 2 ′ so as to cross a pixel region defined by the gate bus line 2 ′ and the source bus line 4 ′.
  • Each CS bus line 6 ′ is provided in common to the R pixel 8 ′, G pixel 10 ′, B pixel 12 ′, and Ye pixel 14 ′ formed in the same row in the liquid crystal display device 100.
  • the CS bus line 6n ′ includes an auxiliary capacitor Cs1R ′, an auxiliary capacitor Cs2R ′, an auxiliary capacitor Cs1G ′, an auxiliary capacitor Cs2G ′, an auxiliary capacitor Cs1B ′, an auxiliary capacitor Cs2B, an “auxiliary capacitor Cs1Ye” and an auxiliary capacitor Cs2Ye. It is connected to the capacitor counter electrode.
  • each auxiliary capacitance and the value of each liquid crystal capacitance have a dependency on the voltage applied to each, but are not essential matters in the present embodiment. So ignore such dependencies. However, this premise does not limit the present embodiment, and can be similarly applied to a case where there is such dependency.
  • the present embodiment is not limited to this, and the CS bus line 6 in Embodiment 1 is not limited thereto.
  • a rectangular wave voltage signal may be supplied to the CS bus line 6 ′.
  • FIG. 11 is a timing chart schematically showing the waveform and timing of each voltage when the liquid crystal display device 100 is driven.
  • FIG. 11A shows the voltage waveform Vs ′ of the data signal supplied from the source driver to the source bus line 4 ′
  • FIG. 11B shows the gate signal supplied from the gate driver to the gate bus line 2l ′
  • FIG. 11C shows the voltage waveform Vg (l + 1) ′ of the gate signal supplied to the gate bus line 2 (l + 1) ′ by the gate driver
  • FIG. ) Shows the voltage waveform Vlc1R ′ of the subpixel electrode of the bright pixel 8a ′ included in the R pixel 8 ′
  • FIG. 11E shows the voltage of the subpixel electrode of the dark pixel 8b ′ included in the R pixel 8 ′.
  • Waveform Vlc2R ′ is shown.
  • the broken line in the figure indicates the voltage waveform COMMON (Vcom) of the counter electrode.
  • the voltage Vgl ′ of the gate signal changes from VgL (low) to VgH (high), whereby the TFT1 ′ and the TFT2 ′ are simultaneously turned on (on state). Accordingly, the voltage of the data signal is applied to the subpixel electrode of the bright pixel 8a ′ and the subpixel electrode of the dark pixel 8b ′ via the source bus line 4 ′, and the subpixel electrode of the bright pixel 8a ′.
  • the voltage of the data signal is also applied to the auxiliary capacitor Cs1R ′ of the bright pixel 8a ′ and the auxiliary capacitor Cs2R ′ of the dark pixel 8b ′ via the source bus line 4 ′, thereby assisting the bright pixel 8a ′.
  • Both the voltage of the capacitance electrode and the auxiliary capacitance electrode of the dark pixel 8b ′ change to the voltage Vs ′ of the data signal.
  • the voltage Vs ′ of the data signal transmitted through the source bus line 4 is a display voltage corresponding to the gradation to be displayed in the pixel, and the TFT is in an on state (sometimes referred to as “selection period”). Are written in the corresponding pixels.
  • the voltage Vgl' of the gate signal changes from VgH to VgL, so that the TFT 1 'and the TFT 2' are simultaneously turned off (off state). Accordingly, the sub-pixel electrode of the bright pixel 8a ′, the sub-pixel electrode of the dark pixel 8b ′, the auxiliary capacitance electrode of the bright pixel 8a ′, and the auxiliary capacitance electrode of the dark pixel 8b ′ are all connected to the source bus line 4 ′. It is electrically insulated (the period in this state may be referred to as “non-selection period”).
  • the voltages Vlc1R ′ and Vlc2R ′ of the respective subpixel electrodes are caused by a pulling phenomenon due to the influence of the parasitic capacitance and the like of the TFT1 ′ and the TFT2 ′. Although it decreases by substantially the same voltage ⁇ Vd ′, this is not an essential matter and will be ignored in the following description.
  • the voltage Vg (l + 1)' of the gate signal changes from VgL to VgH, so that the TFT 3 'becomes conductive. Accordingly, the storage capacitor electrode and the storage capacitor electrode of the dark pixel 8b 'are brought into conduction.
  • ⁇ VR ′ CdR ′ / (Clc2R ′ + Cs2R ′ + CdR ′) (22) Given by.
  • the voltage Vlc1R 'of the subpixel electrode of the bright pixel 8a' does not change at time T3 '.
  • the voltage Vg (l + 1)' of the gate signal changes from VgH to VgL, so that the TFT 3 'is turned off. Accordingly, the storage capacitor electrode of the dark pixel 8b 'is insulated from the storage capacitor electrode.
  • the voltage Vlc2R ′ of the sub-pixel electrode is decreased by approximately the voltage ⁇ Vd ′.
  • this is not an essential matter, so that the TFT 1 ′ and the TFT 2 Similar to the pull-in phenomenon for ', it will be ignored in the following description.
  • Vlc1R ′ Vs ′ (23a)
  • Vlc2R ′ Vs′ ⁇ VR ′ (23b) It becomes.
  • the G pixel 10 ′ is also driven in the same manner, and the difference ⁇ V12G ′ (G pixel) between the effective voltages applied to the respective liquid crystal layers of the bright pixel 10a ′ and the dark pixel 10b ′ included in the G pixel 10 ′. Is sometimes referred to as “ ⁇ V ⁇ ”).
  • ⁇ V12G ′ CdG ′ / (Clc2G ′ + Cs2G ′ + CdG ′) (27) It becomes.
  • ⁇ V12R ′, ⁇ V12G ′, ⁇ V12B ′, and ⁇ V12Ye ′ are expressed as follows.
  • DR ′, DG ′, DG ′, and DYe ′ represent the ratio of the storage capacity to the liquid crystal capacity in each dark pixel (hereinafter also simply referred to as “storage capacity ratio”).
  • DR ′ CdR ′ / Clc2R ′ (30)
  • DB ′ CdB ′ / Clc2B ′ (31)
  • DG ′ CdG ′ / Clc2G ′ (32)
  • DYe ′ CdYe ′ / Clc2Ye ′ (33) Given by.
  • Equations (26 ′) to (29 ′) and Equations (30) to (33) by appropriately changing the value of the storage capacity ratio in each dark pixel, each of the sub-pixels included in each pixel is changed.
  • the difference in effective voltage applied to the liquid crystal layer can be set to a desired value.
  • the effective voltage applied to the respective liquid crystal layers of the sub-pixels included in each pixel can be changed by appropriately changing the value of the auxiliary capacitance in each dark pixel. The difference can be set to a desired value.
  • the value of the storage capacity ratio in each dark pixel or the value of the auxiliary capacity in each dark pixel can be determined so as to reduce the phenomenon of color shift that may occur in the display image.
  • FIG. 12 is a diagram illustrating a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device according to the comparative example. Since tristimulus values have been described in the first embodiment, description thereof is omitted here.
  • the liquid crystal display device according to the comparative example is a VA mode liquid crystal display device, and has the same pixel structure as the liquid crystal display device 100 according to the present embodiment. Each pixel is driven by a driving method.
  • the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant ⁇ (gamma) value. Therefore, when the display screen of the liquid crystal display device according to the comparative example is observed from the front, the phenomenon of color misregistration does not occur.
  • the VA mode liquid crystal display device uses the birefringence effect of the liquid crystal layer and the retardation of the liquid crystal layer has wavelength dispersion, the transmittance varies depending on the wavelength of light.
  • the retardation of the liquid crystal layer is apparently larger at an oblique viewing angle than at the front viewing angle, the dependence of the transmittance variation on the light wavelength is greater than the front viewing angle at the oblique viewing angle.
  • the ⁇ value (more specifically, the value of local ⁇ ) when the screen is observed from an oblique direction is not constant, a color misregistration phenomenon occurs in the oblique direction. Further, the color shift phenomenon does not occur only in the VA mode liquid crystal display device, but also occurs in, for example, the TN mode liquid crystal display device.
  • FIG. 13 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device according to the comparative example.
  • the X value and the Y value rise with substantially the same gradation (approximately 110 gradations). That is, at the polar angle of 60 degrees, the slopes of the graphs indicating the X value and the Y value both change at approximately 110 gradations, and are approximately 110 gradations or more and approximately 130 than the inclinations at approximately 110 gradations or less. The slope below the gradation is larger.
  • the graph indicating the X value and the graph indicating the Y value have turned to a gentle slope from the vicinity of the 150th gradation and the vicinity of the 130th gradation, respectively.
  • Such a profile of the graph showing the X value and the Y value shows that the ⁇ value for each of the X value and the Y value varies greatly, particularly in the range of about 100 gradations to about 150 gradations. Yes.
  • FIG. 14 is a diagram showing a gradation-local ⁇ characteristic at a polar angle of 60 degrees of the liquid crystal display device according to the comparative example.
  • local ⁇ is an index indicating a local gradient of the ⁇ value, and is defined by the mathematical formula (A1) described in the first embodiment.
  • the local ⁇ value related to the X value and the local ⁇ value related to the Y value are substantially equal to each other at about 100 gradations or less.
  • the local ⁇ value related to the X value and the local ⁇ value related to the Y value both show steep rises.
  • the local ⁇ related to the X value increases by about 1.0 in the interval from about 100 gradations to about 150 gradations, and the local ⁇ related to the Y value is about 1. in the interval from about 100 gradations to about 130 gradations. 0 increase.
  • the value of local ⁇ is preferably constant even at an oblique viewing angle.
  • the value of local ⁇ relating to the value and the value of local ⁇ relating to the Y value vary greatly, particularly from about 100 gradations to about 150 gradations.
  • the standard deviation ⁇ of local ⁇ can also be used as an index indicating the magnitude of color shift.
  • a large standard deviation ⁇ corresponds to a large change in local ⁇ for each gradation
  • a small standard deviation ⁇ means a small change in local ⁇ for each gradation, that is, local ⁇ is constant. This is to cope with closeness. Therefore, for example, if the storage capacity ratio in each dark pixel can be optimized so that the value of the standard deviation ⁇ of the local ⁇ becomes smaller, the color shift phenomenon can be reduced.
  • the storage capacity ratio DYe ′ is smaller than the storage capacity ratio DR ′ and the storage capacity ratio DG ′, the difference ⁇ V12Ye between effective voltages applied to the liquid crystal layers of the sub-pixels included in the Ye pixel 14 ′. 'Is smaller than the difference ⁇ V12R' and ⁇ V12G 'in effective voltage applied to the liquid crystal layer of each subpixel included in each of the R pixel 8' and the G pixel 10 '.
  • the effective voltage difference ⁇ V12Ye ′ in the Ye pixel 14 ′ is made smaller than the effective voltage differences ⁇ V12R ′ and ⁇ V12G ′ in the R pixel 8 ′ and the G pixel 10 ′, respectively.
  • the following effects can be obtained.
  • the bright pixels 8a ′ and G pixels 10 ′ included in the R pixel 8 ′ in the low gradation, the bright pixels 8a ′ and G pixels 10 ′ included in the R pixel 8 ′.
  • the bright pixel 10a ′ provided and the bright pixel 14a ′ provided in the Ye pixel 14 ′ mainly contribute, and as the gradation increases, the dark pixel 14b ′ provided in the Ye pixel 14 ′ starts to contribute and the gradation further increases. Accordingly, the dark pixel 8b ′ included in the R pixel 8 ′ and the dark pixel 10b ′ included in the G pixel 10 ′ start to contribute.
  • the luminance of the color including red, green, and yellow as components rises in at least three stages as the gradation increases.
  • the liquid crystal display device 100 according to the present embodiment displays colors including red, green, and yellow as components, the same effect is obtained as when the pixel is divided into at least three subpixels. Is shown. Therefore, in the liquid crystal display device 100 according to the present embodiment, the local ⁇ particularly with respect to the X value and the Y value can be made more constant.
  • the effective voltage difference ⁇ V12Ye ′ in the Ye pixel 14 ′ is different between the R pixel 8 ′ and the G pixel 10 ′. Is equal to the difference ⁇ V12R ′ and ⁇ V12G ′ in effective voltage at.
  • the bright pixel 8a ′ included in the R pixel 8 ′, the bright pixel 10a ′ included in the G pixel 10 ′, and the bright pixel included in the Ye pixel 14 ′ As the pixel 14a ′ mainly contributes and the gradation increases, the dark pixel 14b ′ included in the Ye pixel 14 ′, the dark pixel 8b ′ included in the R pixel 8 ′, and the dark pixel 10b ′ included in the G pixel 10 ′ Begin to contribute uniformly. Therefore, in the liquid crystal display device according to the comparative example, the luminance of the color including red, green, and yellow as components only rises in two stages.
  • the liquid crystal display device 100 sets red, green, and yellow by setting the storage capacity ratio DYe ′ to be smaller than the storage capacity ratio DR ′ and the storage capacity ratio DG ′. Since the luminance of the color included as a component can be raised in at least three stages as the gradation increases, the local ⁇ particularly for the X value and the Y value can be increased more than the liquid crystal display device according to the comparative example. Can be close to constant. Therefore, the liquid crystal display device 100 can effectively suppress the phenomenon of color misregistration at an oblique viewing angle.
  • FIG. 15 is a diagram showing a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device 100 according to the present embodiment.
  • the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant ⁇ (gamma) value. Therefore, when the display screen of the liquid crystal display device 100 according to the present embodiment is observed from the front, the phenomenon of color misregistration does not occur.
  • FIG. 16 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device 100 according to the present embodiment.
  • the change in the ⁇ value in the range of approximately 100 gradations to approximately 150 gradations is smaller than that of the liquid crystal display device according to the comparative example.
  • the curve of the graph indicating the X value and the Y value is closer to the ideal curve with a constant ⁇ value, so that the phenomenon of color shift is suppressed.
  • FIG. 17 is a diagram showing the gradation-local ⁇ characteristic at the polar angle of 60 degrees of the liquid crystal display device 100 according to the present embodiment.
  • the value of local ⁇ related to the X value and the value of local ⁇ related to the Y value take substantially constant values in a range from about 20 gradations to about 220 gradations. This is in contrast to the fact that the value of local ⁇ relating to the X value and the value of local ⁇ relating to the Y value in the liquid crystal display device according to the comparative example change greatly in the range of approximately 100 gradations to approximately 150 gradations. It is.
  • the effective voltage difference ⁇ V12Ye ′ in the Ye pixel 14 ′ is changed to the effective voltage difference ⁇ V12R ′ in the R pixel 8 ′ and the G pixel 10 ′.
  • ⁇ V12G ′ the phenomenon of color shift at an oblique viewing angle can be effectively suppressed.
  • FIG. 18A shows the ratio (CdYe ′ / CdG ′) of the storage capacitor CdYe ′ to the storage capacitor CdG ′ set experimentally and Y corresponding to each ratio in the liquid crystal display device 100 according to the present embodiment. It is a table
  • FIG. 18B is a graph showing the relationship between the ratio CdYe ′ / CdG ′ and the standard deviation ⁇ .
  • the liquid crystal display device 100 according to the present embodiment can be expressed as an optimized liquid crystal display device so that each storage capacitor can most effectively suppress the phenomenon of color misregistration. .
  • the liquid crystal display device 1 and the liquid crystal display device 100 display yellow obtained by a combination of a pixel that displays each of the three primary colors red, green, and blue and red and green. And the effective voltage difference ⁇ V12Ye ( ⁇ V12Ye ′) for the pixel displaying yellow, and the effective voltage difference ⁇ V12R ( ⁇ V12R ′) for each of the pixel displaying red and the pixel displaying green.
  • ⁇ V12Ye ⁇ V12Ye ′
  • ⁇ V12R effective voltage difference
  • the liquid crystal display device includes a pixel that displays white obtained by a combination of red, green, and blue, instead of a pixel that displays yellow obtained by a combination of red and green,
  • the difference in effective voltage for pixels that display white may be configured to be smaller than the difference in effective voltage among pixels that display red, pixels that display green, and pixels that display blue.
  • the liquid crystal display device includes three primary colors other than red, green, and blue, for example, pixels that individually display the three primary colors of cyan (C), magenta (M), and yellow (Y).
  • the effective voltage difference may be made smaller than the effective voltage difference for pixels that display at least two colors (for example, pixels that display cyan and pixels that display magenta).
  • the liquid crystal display device has three primary colors. (C1, C2, C3) and a pixel for displaying a specific mixed color (C1 + C2, C2 + C3, C3 + C1, or C1 + C2 + C3) obtained by combining a plurality of specific primary colors among the three primary colors, It can be expressed as a configuration in which the difference in effective voltage for the pixels displaying the plurality of specific primary colors is different from the difference in effective voltage for the pixels displaying the specific color mixture.
  • the liquid crystal display device is displayed using a plurality of specific primary colors among the three primary colors and a specific color mixture obtained by combining the specific primary colors. Since the gradation-stimulus value characteristic at the oblique viewing angle for the image to be displayed can be brought close to the gradation-stimulus value characteristic at the front viewing angle, the phenomenon of color shift at the oblique viewing angle can be suppressed.
  • the display panel according to the present invention includes a plurality of pixels that individually display three primary colors and a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors;
  • Each of the pixels includes a first subpixel and a second subpixel, and each of the first subpixel and the second subpixel is opposed to the counter electrode through a liquid crystal layer.
  • the sub-pixel electrode and the second sub-pixel in the first sub-pixel of a pixel that respectively displays a plurality of specific primary colors among the three primary colors.
  • a first sub-pixel for a pixel that generates a first potential difference with the sub-pixel electrode in the pixel and displays a specific mixed color obtained by combining the plurality of specific primary colors among the three primary colors.
  • a second potential difference different from the first potential difference is generated between the sub-pixel electrode in the pixel and the sub-pixel electrode in the second sub-pixel.
  • the display panel configured as described above has an oblique viewing angle with respect to an image displayed using a plurality of specific primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors.
  • each of the first subpixel and the second subpixel is insulated from an auxiliary capacitance electrode connected to the subpixel electrode.
  • At least one auxiliary capacitance formed by an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via a layer, and the display panel has a pixel electrode voltage with respect to the sub-pixel electrode.
  • the second potential difference is generated between the sub-pixel electrode and the sub-pixel electrode in the second sub-pixel, and the auxiliary capacitance of each of the pixels displaying the specific primary colors is displayed. It is preferable that the capacitance value and the capacitance value of the auxiliary capacitance for the pixel displaying the specific color mixture are different from each other.
  • an auxiliary capacitance voltage is applied to the auxiliary capacitance counter electrode, whereby the specific plurality of specific display devices For each of the pixels displaying primary colors, the first potential difference is generated between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel, and the specific color mixture Multi-pixel driving (Multi Pixel) for generating the second potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel.
  • Multi Pixel Multi-pixel driving
  • Each pixel is driven by a drive method, and a capacitance value of the auxiliary capacitor for each pixel that displays the specific primary colors and a pixel that displays the specific color mixture.
  • the capacity value of the auxiliary capacity is different from each other, an image displayed using a specific plurality of primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors.
  • the gradation-stimulus value characteristic at the oblique viewing angle can be brought close to the gradation-stimulus value characteristic at the front viewing angle.
  • the display panel includes pixels that display colors other than the three primary colors in addition to the pixels that individually display the three primary colors, and each pixel is driven by a multi-pixel driving method. In this case, it is possible to effectively suppress a color shift phenomenon caused by a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel.
  • the capacitance value of the auxiliary capacitance for the pixel that displays the specific mixed color is greater than 0.1 times the capacitance value of the auxiliary capacitance for the pixel that respectively displays the specific plurality of primary colors, and It is preferable that the capacitance value is smaller than the capacitance value of the auxiliary capacitor for each pixel displaying the specific plurality of primary colors.
  • the inventor has found from the experimental data when each pixel is driven by the multi-pixel driving method that the capacitance value of the auxiliary capacitor for the pixel displaying the specific color mixture displays the specific primary colors respectively.
  • the gradation-stimulus value characteristic at an oblique viewing angle for an image displayed using a plurality of primary colors and a specific color mixture obtained by combining the specific primary colors is a gradation-stimulus value at a front viewing angle. We found that it is closer to the characteristics. Therefore, according to the above configuration, the phenomenon of color misregistration can be more effectively suppressed.
  • the second sub-pixel of each of the plurality of pixels includes a storage capacitor electrode and a storage capacitor facing the storage capacitor electrode through an insulating layer.
  • a transistor comprising: at least one storage capacitor formed by a counter electrode; a source electrode electrically connected to the storage capacitor electrode; and a drain electrode electrically connected to the sub-pixel electrode.
  • the display panel includes the specific plurality of primary colors by electrically connecting a source electrode and a drain electrode of the transistor after a pixel electrode voltage is applied to the sub-pixel electrode. For the pixel to be displayed, the first potential difference between the subpixel electrode in the first subpixel and the subpixel electrode in the second subpixel.
  • a capacity value of the storage capacitor for each pixel that displays the specific plurality of primary colors and a capacity value of the storage capacitor for the pixel that displays the specific color mixture are different from each other. It is preferable.
  • the source electrode and the drain electrode included in the transistor are electrically connected to each other so that the specific plurality of primary colors can be obtained.
  • the first potential difference is generated between the subpixel electrode in the first subpixel and the subpixel electrode in the second subpixel, and the specific color mixture is displayed.
  • Each pixel is driven by the display, and the capacitance value of the storage capacitor and the specific color mixture for the pixels displaying the specific primary colors are displayed.
  • the capacitance values of the storage capacitors of the pixels are different from each other, they are displayed using a plurality of specific primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors.
  • the gradation-stimulus value characteristic at the oblique viewing angle can be brought close to the gradation-stimulus value characteristic at the front viewing angle.
  • the display panel includes pixels that display colors other than the three primary colors in addition to the pixels that individually display the three primary colors, and each pixel has a driving system corresponding to the 3TFT driving system.
  • each pixel has a driving system corresponding to the 3TFT driving system.
  • the capacity value of the storage capacitor for the pixel displaying the specific color mixture is smaller than the capacity value of the storage capacitor for the pixel displaying each of the specific plurality of primary colors.
  • the inventor determines that the capacitance value of the storage capacitor for the pixel displaying the specific color mixture is the specific plurality of primary colors.
  • the display is performed using a specific plurality of primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors. It has been found that the gradation-stimulus value characteristic at an oblique viewing angle for an image is closer to the gradation-stimulus characteristic at a front viewing angle. Therefore, according to the above configuration, the phenomenon of color misregistration can be more effectively suppressed.
  • the specific primary colors are specific two primary colors among the three primary colors, and the specific mixed color is obtained by combining the specific two primary colors.
  • the gradation-stimulation at an oblique viewing angle for an image displayed using two specific primary colors of the three primary colors and a mixed color obtained by combining the two specific primary colors Since the value characteristic can be brought close to the gradation-stimulus value characteristic at the front viewing angle, the phenomenon of color misregistration can be effectively suppressed.
  • the three primary colors are red, green, and blue
  • the specific two primary colors are red and green
  • the specific mixed color is yellow.
  • the phenomenon of color misregistration can be effectively suppressed. Can do.
  • liquid crystal display device provided with the display panel is also included in the scope of the present invention.
  • the present invention can be suitably applied to a display panel that displays an image using liquid crystal.
  • the present invention can be suitably applied to a display panel that displays a color image by a combination of three primary colors and colors other than the three primary colors. Further, it can be suitably applied to a liquid crystal display device including such a display panel.
  • 1,100 Liquid crystal display device 2 2 'Gate bus line 4, 4' Source bus line 6, 6 'CS bus line 8, 8' R pixel 8a, 8a 'Bright pixel (first subpixel) Dark pixels (second sub-pixels) of 8b and 8b ′ R pixels Bright pixels (first sub-pixels) of 10, 10 ′ G pixels 10a, 10a ′ G pixels Dark pixels (second subpixels) of 10b and 10b ′ G pixels Bright pixels (first sub-pixels) of the 12 and 12 ′ B pixels 12a and 12a ′ B pixels Dark pixels (second subpixels) of 12b and 12b ′ B pixels 14, 14 ′ Ye pixels 14a, 14a ′ Ye pixel bright pixels (first sub-pixel) Dark pixels (second subpixels) of 14b and 14b ′ Ye pixels Cs1R Auxiliary capacitor Cs1G Auxiliary capacitor Cs1B Auxiliary capacitor Cs1Ye Auxiliary capacitor Cs2R Auxiliary capacitor Cs2G Auxiliary

Abstract

The disclosed display panel, which the disclosed liquid crystal display device (1) is provided with, is provided with R pixels (8), G pixels (10), and B pixels (12) as pixels that separately display the three primary colors of red, green, and blue, and is provided with Ye pixels (14) as pixels that display a color other than the three primary colors. Each pixel is provided with a first subpixel and a second subpixel. A first electrical potential difference is generated between the subpixel electrode of the aforementioned first subpixel and the subpixel electrode of the aforementioned second subpixel of one pixel that displays at least one primary color of the aforementioned three primary colors, and a second electrical potential difference that is different from the aforementioned first electrical potential difference is generated between the subpixel electrode of the first subpixel and the subpixel electrode of the second subpixel of the pixels that display the aforementioned color other than the three primary colors.

Description

表示パネル、および、液晶表示装置Display panel and liquid crystal display device
　本発明は、液晶を用いて画像を表示する表示パネルに関する。特に、３原色と３原色以外の色との組み合わせによってカラー画像を表示する表示パネルに関する。また、そのような表示パネルを備えた液晶表示装置に関する。 The present invention relates to a display panel that displays an image using liquid crystal. In particular, the present invention relates to a display panel that displays a color image by a combination of three primary colors and a color other than the three primary colors. The present invention also relates to a liquid crystal display device including such a display panel.
　近年、液晶表示装置は、テレビ受像機、パーソナル・コンピュータのモニタ装置、および、携帯液晶端末等に広く用いられている。これらの用途に用いられる液晶表示装置においては、ユーザが、表示画像を様々な方向から見ることがあるため、高い視野角特性が求められている。 In recent years, liquid crystal display devices are widely used in television receivers, personal computer monitor devices, portable liquid crystal terminals, and the like. In a liquid crystal display device used for these applications, since a user may view a display image from various directions, high viewing angle characteristics are required.
　視野角特性が低下すると、特に斜め視野角において、表示画像が、正面視野角における色と異なった色調に見える「色ずれ」と呼ばれる現象が生じることが知られている。 It is known that when the viewing angle characteristics deteriorate, a phenomenon called “color shift” occurs in which the displayed image looks different from the color at the front viewing angle, particularly at an oblique viewing angle.
　特許文献１には、薄膜トランジスタ（ＴＦＴ：Ｔｈｉｎ　Ｆｉｌｍ　Ｔｒａｎｓｉｓｔｏｒ）に接続されている第１副画素電極に印加される電圧と、当該第１副画素電極に対して容量性結合されている第２副画素電極に印加される電圧との、各副画素における比率を互いに異ならせることによって、視野角特性の改善を図ることのできる液晶表示装置が開示されている。 Patent Document 1 discloses a voltage applied to a first subpixel electrode connected to a thin film transistor (TFT: Thin Film Transistor) and a second subpixel capacitively coupled to the first subpixel electrode. There has been disclosed a liquid crystal display device capable of improving the viewing angle characteristics by making the ratio of the voltage applied to the electrodes different in each sub-pixel.
　特許文献２には、青色／シアン色絵素について、第１副絵素に印加される電圧と第２副絵素に印加される電圧との電圧差を小さくすることによって、ＶＡ型液晶の波長分散に起因するＲＧＢ各色の視野特性の違いを緩和し、斜め視野角における色ずれの改善を図ることのできる液晶表示装置が開示されている。 In Patent Document 2, for blue / cyan color pixels, the wavelength dispersion of the VA liquid crystal is reduced by reducing the voltage difference between the voltage applied to the first sub-pixel and the voltage applied to the second sub-pixel. There is disclosed a liquid crystal display device that can alleviate the difference in viewing characteristics of each color of RGB due to the above and improve the color shift at an oblique viewing angle.
日本国公開特許公報「特開２００６－４８０５５号公報（２００６年２月１６日公開）」Japanese Patent Publication “Japanese Patent Laid-Open No. 2006-48055” (published on February 16, 2006) 国際公開番号ＷＯ２００８／０１８５５２Ａ１（２００８年２月１４日公開）International Publication Number WO2008 / 018552A1 (published February 14, 2008)
　しかしながら、特許文献１および特許文献２に開示された技術を用いたとしても、色ずれの現象を抑制する効果は限定的であるという問題がある。 However, even if the techniques disclosed in Patent Document 1 and Patent Document 2 are used, there is a problem that the effect of suppressing the phenomenon of color misregistration is limited.
　発明者は、その理由として、各色の画素を２つの副画素に分割することを前提とする特許文献１および特許文献２に開示された技術では、特に中間調において、斜め視野角におけるｌｏｃａｌγの値が、正面視野角におけるｌｏｃａｌγの値と大きく異なってしまうため、斜め視野角において急峻な輝度変化が生じてしまい、斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることが困難なためであるとの知見を得た。 The inventor, as the reason, in the technique disclosed in Patent Document 1 and Patent Document 2 on the premise that each color pixel is divided into two sub-pixels, the value of local γ at an oblique viewing angle, particularly in a halftone. However, since the local γ value is significantly different from the local γ value at the front viewing angle, a steep luminance change occurs at the oblique viewing angle, and the gradation-stimulus value characteristic at the oblique viewing angle is We obtained the knowledge that it was difficult to get close to the characteristics.
　発明者の得た上記知見によれば、例えば、各色の画素を３つ以上の副画素に分割することによって、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に改善することができる。しかしながら、副画素の数が増大すると、液晶パネル（表示パネル）の設計が複雑になり、コストが増大するという問題が生じることになる。 According to the above knowledge obtained by the inventor, for example, by dividing each color pixel into three or more subpixels, the phenomenon of color misregistration caused by a steep luminance change at an oblique viewing angle is effectively improved. be able to. However, when the number of sub-pixels increases, the design of the liquid crystal panel (display panel) becomes complicated, resulting in an increase in cost.
　一方で、最近、赤緑青の３原色に対応する画素に加えて、３原色以外の原色に対応する画素を備えることにより、３原色と３原色以外の色との組み合わせによってカラー画像を表示する液晶表示装置（以下、「多原色型の液晶表示装置」と呼ぶ）が開発されている。多原色型の液晶表示装置は、赤緑青の３原色のみを用いて表示を行う従来の液晶表示装置に比べて、表現できる色の数を格段に増加させることができる。なお、多原色型の液晶表示装置の例としては、例えば、赤緑青の３原色と黄色との組み合わせによってカラー画像を表示する液晶表示装置がある。 On the other hand, recently, in addition to pixels corresponding to the three primary colors of red, green, and blue, a liquid crystal that displays a color image by a combination of three primary colors and colors other than the three primary colors by including pixels corresponding to primary colors other than the three primary colors. Display devices (hereinafter referred to as “multi-primary liquid crystal display devices”) have been developed. The multi-primary color liquid crystal display device can significantly increase the number of colors that can be expressed, as compared with a conventional liquid crystal display device that performs display using only the three primary colors of red, green, and blue. As an example of a multi-primary color liquid crystal display device, for example, there is a liquid crystal display device that displays a color image by a combination of three primary colors of red, green, and blue and yellow.
　発明者は、このような多原色型の液晶表示装置においては、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化を抑制し、色ずれの現象を効果的に抑制することが可能であるとの知見を得た。 The inventor has effectively reduced the phenomenon of color misregistration in such a multi-primary type liquid crystal display device by suppressing a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel. It was found that it is possible to suppress it.
　本発明は、上記の問題に鑑み、発明者による上記の知見に基づいてなされたものであり、その目的は、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に抑制することのできる多原色型の液晶表示装置を実現することにある。 The present invention has been made on the basis of the above-mentioned knowledge by the inventor in view of the above problems, and its object is to achieve steep luminance at an oblique viewing angle without increasing the number of sub-pixels in each color pixel. An object of the present invention is to realize a multi-primary color type liquid crystal display device capable of effectively suppressing the phenomenon of color misregistration caused by a change.
　発明者は、上記の問題に関し、３原色に対応する画素の各々が備える副画素電極に印加される電圧の画素毎の電圧差と、当該３原色以外の色に対応する画素の備える副画素電極に印加される電圧の電位差とを、互いに異ならせることによって、斜め視野角における色ずれの現象を抑制することができるという知見を得た。本発明に係る表示パネルは、発明者によって得られた上記の知見に基づいてなされたものである。 The inventor relates to the above problem, a voltage difference applied to each subpixel electrode included in each of the pixels corresponding to the three primary colors, and a subpixel electrode included in the pixel corresponding to a color other than the three primary colors. It was found that the phenomenon of color misregistration at an oblique viewing angle can be suppressed by making the potential difference between the voltages applied to the two different from each other. The display panel according to the present invention has been made based on the above findings obtained by the inventors.
　本発明に係る表示パネルは、３原色、および、前記３原色のうち特定の複数の原色を組み合わせることにより得られる特定の混色を個別に表示する複数の画素と、前記複数の画素の各々について、第１の副画素と、第２の副画素と、を備え、前記第１の副画素および前記第２の副画素のそれぞれは、対向電極と、液晶層を介して前記対向電極に対向する副画素電極とによって形成された液晶容量と、を有している表示パネルであって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第１の電位差とは異なる第２の電位差を生じさせる、ことを特徴としている。 The display panel according to the present invention has three primary colors and a plurality of pixels that individually display a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors, and each of the plurality of pixels. A first sub-pixel and a second sub-pixel, each of the first sub-pixel and the second sub-pixel being opposed to the counter electrode and the counter electrode via a liquid crystal layer. A display panel having a liquid crystal capacitor formed by a pixel electrode, wherein the sub-pixel electrode and the first sub-pixel electrode in the first sub-pixel of the pixel respectively displaying the specific plurality of primary colors A first potential difference is generated between the sub-pixel electrode of the second sub-pixel and the sub-pixel electrode and the second sub-pixel of the first sub-pixel of the pixel displaying the specific color mixture. In pixel Wherein between the sub-pixel electrode, the cause different second potential difference between the first potential difference, is characterized in that.
　上記のように構成された本発明に係る表示パネルは、前記３原色のうち特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に第１の電位差を生じさせると共に、前記３原色のうち前記特定の複数の原色を組み合わせることにより得られる特定の混色を表示する画素についての、第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第１の電位差とは異なる第２の電位差を生じさせる。 In the display panel according to the present invention configured as described above, the sub-pixel electrode and the second sub-pixel in the first sub-pixel of a pixel that respectively displays a plurality of specific primary colors among the three primary colors. A first sub-pixel for a pixel that generates a first potential difference with the sub-pixel electrode in the pixel and displays a specific mixed color obtained by combining the plurality of specific primary colors among the three primary colors. A second potential difference different from the first potential difference is generated between the sub-pixel electrode in the pixel and the sub-pixel electrode in the second sub-pixel.
　上記のように構成された表示パネルは、前記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての、斜め視野角における急峻な輝度変化を抑制することによって、斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることができるので、斜め視野角における色ずれの現象を効果的に抑制することができる。 The display panel configured as described above has an oblique viewing angle with respect to an image displayed using a plurality of specific primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors. By suppressing the steep luminance change in the image, the gradation-stimulus value characteristic at the oblique viewing angle can be brought close to the gradation-stimulus value characteristic at the front viewing angle, so that the phenomenon of color shift at the oblique viewing angle is effective. Can be suppressed.
　すなわち、上記の構成によれば、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に抑制することができる。 That is, according to the above configuration, it is possible to effectively suppress the phenomenon of color shift caused by a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel.
　以上のように、本発明に係る表示パネルは、３原色、および、前記３原色のうち特定の複数の原色を組み合わせることにより得られる特定の混色を個別に表示する複数の画素と、前記複数の画素の各々について、第１の副画素と、第２の副画素と、を備え、前記第１の副画素および前記第２の副画素のそれぞれは、対向電極と、液晶層を介して前記対向電極に対向する副画素電極とによって形成された液晶容量と、を有している表示パネルであって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第１の電位差とは異なる第２の電位差を生じさせる、ことを特徴としている。 As described above, the display panel according to the present invention includes a plurality of pixels that individually display three primary colors and a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors; Each of the pixels includes a first subpixel and a second subpixel, and each of the first subpixel and the second subpixel is opposed to the counter electrode through a liquid crystal layer. A display panel having a liquid crystal capacitor formed by a sub-pixel electrode facing the electrode, the sub-pixel in the first sub-pixel for each of the pixels displaying the specific primary colors A first potential difference between the pixel electrode and the sub-pixel electrode in the second sub-pixel, and the sub-pixel electrode in the first sub-pixel for the pixel displaying the specific color mixture; The second Between the subpixel electrodes in sub-pixels, giving rise to different second potential difference between the first potential difference, it is characterized in that.
　上記のように構成された表示パネルによれば、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に抑制することができる。 According to the display panel configured as described above, it is possible to effectively suppress the phenomenon of color shift caused by a steep luminance change at an oblique viewing angle without increasing the number of subpixels in each color pixel. it can.
本発明の第１の実施形態に係る液晶表示装置の備える表示パネルの等価回路を示す図である。It is a figure which shows the equivalent circuit of the display panel with which the liquid crystal display device which concerns on the 1st Embodiment of this invention is provided. 本発明の第１の実施形態に係る液晶表示装置を駆動する際の各電圧の波形およびタイミングを模式的に示すタイミングチャートであり、（ａ）は、ソースドライバがソースバスラインに供給するデータ信号の電圧波形を示しており、（ｂ）は、ＣＳドライバがｎ本目のＣＳバスラインに供給する補助容量駆動信号の電圧波形を示しており、（ｃ）はＣＳドライバがｎ＋１本目のＣＳバスラインに供給する補助容量駆動信号の電圧波形を示しており、（ｄ）は、ゲートドライバがゲートバスラインに供給するゲート信号の電圧波形を示しており、（ｅ）は、赤色を表示する画素の備える明画素の副画素電極の電圧波形を示しており、（ｆ）は、赤色を表示する画素の備える暗画素の副画素電極の電圧波形を示している。2 is a timing chart schematically showing waveforms and timings of respective voltages when driving the liquid crystal display device according to the first embodiment of the present invention, wherein (a) is a data signal supplied from a source driver to a source bus line; (B) shows the voltage waveform of the auxiliary capacitor drive signal supplied to the n th CS bus line by the CS driver, and (c) shows the n + 1 th CS bus line by the CS driver. (D) shows the voltage waveform of the gate signal supplied to the gate bus line by the gate driver, and (e) shows the voltage waveform of the pixel displaying red. The voltage waveform of the subpixel electrode of the bright pixel provided is shown, and (f) shows the voltage waveform of the subpixel electrode of the dark pixel provided in the pixel displaying red. 本発明の第１の実施形態において、比較例に係る液晶表示装置の、正面視角における階調―ＸＹＺ値特性を示す図である。In the 1st Embodiment of this invention, it is a figure which shows the gradation -XYZ value characteristic in a front viewing angle of the liquid crystal display device which concerns on a comparative example. 本発明の第１の実施形態において、比較例に係る液晶表示装置の、極角６０度における階調―ＸＹＺ値特性を示す図である。In the 1st Embodiment of this invention, it is a figure which shows the gradation -XYZ value characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on a comparative example. 本発明の第１の実施形態において、比較例に係る液晶表示装置の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。In the 1st Embodiment of this invention, it is a figure which shows the gradation-local-gamma characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on a comparative example. 本発明の第１の実施形態に係る液晶表示装置の、正面視角における階調―ＸＹＺ値特性を示す図である。It is a figure which shows the gradation-XYZ value characteristic in the front viewing angle of the liquid crystal display device which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態に係る液晶表示装置の、極角６０度における階調―ＸＹＺ値特性を示す図である。It is a figure which shows the gradation-XYZ value characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態に係る液晶表示装置の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。It is a figure which shows the gradation-local-gamma characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態において、視野角特性を改善するための最適な補助容量の比を説明するためのものであって、（ａ）は、黄色画素における補助容量の緑色画素における補助容量に対する比と、各比に対応するＹ値のｌｏｃａｌγの中間調における標準偏差σとの関係を示す表であり、（ｂ）は、上記比と、上記標準偏差σとの関係を示すグラフである。In the first embodiment of the present invention, an optimal auxiliary capacitance ratio for improving viewing angle characteristics is described, and (a) shows an auxiliary capacitance in a green pixel of an auxiliary capacitance in a yellow pixel. And (b) is a graph showing the relationship between the ratio and the standard deviation σ, and the relationship between the ratio and the standard deviation σ in the halftone of the local γ of the Y value corresponding to each ratio. . 本発明の第２の実施形態に係る液晶表示装置の備える表示パネルの等価回路を示す図である。It is a figure which shows the equivalent circuit of the display panel with which the liquid crystal display device which concerns on the 2nd Embodiment of this invention is provided. 本発明の第２の実施形態に係る液晶表示装置を駆動する際の各電圧の波形およびタイミングを模式的に示すタイミングチャートであり、（ａ）は、ソースドライバがソースバスラインに供給するデータ信号の電圧波形を示しており、（ｂ）は、ゲートドライバがｌ本目のゲートバスラインに供給するゲート信号の電圧波形を示しており、（ｃ）は、ゲートドライバがｌ＋１本目のゲートバスラインに供給するゲート信号の電圧波形を示しており、（ｄ）は、赤色を表示する画素の備える明画素の副画素電極の電圧波形を示しており、（ｅ）は、赤色を表示する画素の備える暗画素の副画素電極の電圧波形を示している。It is a timing chart which shows typically the waveform and timing of each voltage at the time of driving the liquid crystal display concerning a 2nd embodiment of the present invention, and (a) is a data signal which a source driver supplies to a source bus line (B) shows the voltage waveform of the gate signal supplied by the gate driver to the l-th gate bus line, and (c) shows the voltage waveform of the gate driver supplied to the l + 1-th gate bus line. The voltage waveform of the gate signal to be supplied is shown, (d) shows the voltage waveform of the sub-pixel electrode of the bright pixel included in the pixel displaying red, and (e) is included in the pixel displaying red. The voltage waveform of the subpixel electrode of a dark pixel is shown. 本発明の第２の実施形態において、比較例に係る液晶表示装置の、正面視角における階調―ＸＹＺ値特性を示す図である。In the 2nd Embodiment of this invention, it is a figure which shows the gradation -XYZ value characteristic in a front viewing angle of the liquid crystal display device which concerns on a comparative example. 本発明の第２の実施形態において、比較例に係る液晶表示装置の、極角６０度における階調―ＸＹＺ値特性を示す図である。In the 2nd Embodiment of this invention, it is a figure which shows the gradation -XYZ value characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on a comparative example. 本発明の第２の実施形態において、比較例に係る液晶表示装置の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。In the 2nd Embodiment of this invention, it is a figure which shows the gradation-local-gamma characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on a comparative example. 本発明の第２の実施形態に係る液晶表示装置の、正面視角における階調―ＸＹＺ値特性を示す図である。It is a figure which shows the gradation-XYZ value characteristic in the front viewing angle of the liquid crystal display device which concerns on the 2nd Embodiment of this invention. 本発明の第２の実施形態に係る液晶表示装置の、極角６０度における階調―ＸＹＺ値特性を示す図である。It is a figure which shows the gradation-XYZ value characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on the 2nd Embodiment of this invention. 本発明の第２の実施形態に係る液晶表示装置の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。It is a figure which shows the gradation-local gamma characteristic in the polar angle of 60 degree | times of the liquid crystal display device which concerns on the 2nd Embodiment of this invention. 本発明の第２の実施形態において、視野角特性を改善するための最適な蓄積容量の比を説明するためのものであって、（ａ）は、黄色画素における蓄積容量の緑色画素における蓄積容量に対する比と、各比に対応するＹ値のｌｏｃａｌγの中間調における標準偏差σとの関係を示す表であり、（ｂ）は、上記比と、上記標準偏差σとの関係を示すグラフである。In the second embodiment of the present invention, the optimum storage capacitor ratio for improving the viewing angle characteristic is described, and (a) shows the storage capacitor in the green pixel of the storage capacitor in the yellow pixel. And (b) is a graph showing the relationship between the ratio and the standard deviation σ, and the relationship between the ratio and the standard deviation σ in the halftone of the local γ of the Y value corresponding to each ratio. .
　〔実施形態１〕
　本発明に係る第１の実施形態について、図１～図９を参照して以下に説明する。以下の説明では、本発明の効果が顕著に現れる、誘電異方性が負の液晶材料を用いた垂直配向型液晶表示装置（ＶＡモードの液晶表示装置）を例示するが、本発明はこれに限定されず、例えばＴＮモードの液晶表示装置にも適用できる。 Embodiment 1
A first embodiment according to the present invention will be described below with reference to FIGS. In the following description, a vertical alignment type liquid crystal display device (VA mode liquid crystal display device) using a liquid crystal material having a negative dielectric anisotropy, in which the effect of the present invention appears remarkably, will be described. For example, the present invention can be applied to a TN mode liquid crystal display device.
　（液晶表示装置１の構成）
　図１は、本実施形態に係る液晶表示装置１の備える表示パネルにおける、マルチ画素構造を有する画素の等価回路を示す図である。図１に示すように、液晶表示装置１は、表示パネルにおいて、複数のゲートバスライン２、複数のソースバスライン４、複数のスイッチング素子ＴＦＴ１、複数のスイッチング素子ＴＦＴ２、複数の補助容量Ｃｓ１、複数の補助容量Ｃｓ２、および、複数のＣＳバスライン６を備えている。液晶表示装置１の表示パネルには複数の画素が形成されており、液晶表示装置１は、各画素をマルチ画素駆動（Multi Pixel Drive）方式によって駆動する。各画素はいずれも液晶層と、当該液晶層に電圧を印加する電極とを有し、行および列を有するマトリックス状に配列されている。 (Configuration of the liquid crystal display device 1)
FIG. 1 is a diagram showing an equivalent circuit of a pixel having a multi-pixel structure in a display panel included in the liquid crystal display device 1 according to the present embodiment. As shown in FIG. 1, the liquid crystal display device 1 includes a plurality of gate bus lines 2, a plurality of source bus lines 4, a plurality of switching elements TFT1, a plurality of switching elements TFT2, a plurality of auxiliary capacitors Cs1, and a plurality of display buses. The auxiliary capacitor Cs2 and a plurality of CS bus lines 6 are provided. A plurality of pixels are formed on the display panel of the liquid crystal display device 1, and the liquid crystal display device 1 drives each pixel by a multi-pixel drive method. Each pixel has a liquid crystal layer and an electrode for applying a voltage to the liquid crystal layer, and is arranged in a matrix having rows and columns.
　図１において、ゲートバスライン２ｌは、ｌ（ただしｌは正の整数）本目のゲートバスライン２を示している。また、ソースバスライン４ｍは、ｍ（ただしｍは正の整数）本目のソースバスライン４ｍを示している。また、ＣＳバスライン６ｎは、ｎ（ただしｎは正の整数）本目のＣＳバスライン６を示している。 In FIG. 1, the gate bus line 2 l indicates the l-th gate bus line 2 (where l is a positive integer). The source bus line 4m indicates the m-th source bus line 4m (where m is a positive integer). The CS bus line 6n indicates the nth (where n is a positive integer) CS bus line 6.
　（ドライバ）
　特に図示はしないが、液晶表示装置１には、各ゲートバスライン２にゲート信号を供給するゲートドライバと、各ソースバスライン４にデータ信号を供給するソースドライバと、各ＣＳバスライン６に補助容量駆動信号を供給するＣＳドライバとが、それぞれ接続されている。これらのドライバはいずれも、図示しない制御回路から出力された制御信号に基づいて動作する。 (driver)
Although not specifically shown, the liquid crystal display device 1 includes a gate driver that supplies a gate signal to each gate bus line 2, a source driver that supplies a data signal to each source bus line 4, and an auxiliary to each CS bus line 6. A CS driver that supplies a capacitive drive signal is connected to each other. Each of these drivers operates based on a control signal output from a control circuit (not shown).
　（画素構造）
　複数のゲートバスライン２および複数のソースバスライン４は、図示しない絶縁膜を介して、互いに交差して形成されている。液晶表示装置１では、１つのゲートバスライン２と１つのソースバスライン４とによって画定される領域ごとに、１つの画素が形成される。当該画素は、複数の互いに異なる種類の色のうちいずれかを個別に表示する。本実施形態においては、上記複数の互いに異なる種類の色には、複数の原色、および、該複数の原色のうち少なくとも２つの原色を組み合わせることによって得られる少なくとも１つ以上の色が含まれる。以下では、特に、上記複数の互いに異なる種類の色が、光の３原色（以下、単に「３原色」と呼ぶ）として、赤色、緑色、および青色を含み、上記複数の原色のうち少なくとも２つの原色を組み合わせることによって得られる色として、黄色（赤色および緑色の組み合わせ）を含む場合について説明する。 (Pixel structure)
The plurality of gate bus lines 2 and the plurality of source bus lines 4 are formed so as to intersect each other via an insulating film (not shown). In the liquid crystal display device 1, one pixel is formed for each region defined by one gate bus line 2 and one source bus line 4. The pixel individually displays one of a plurality of different types of colors. In the present embodiment, the plurality of different types of colors include a plurality of primary colors and at least one or more colors obtained by combining at least two primary colors among the plurality of primary colors. In the following, in particular, the plurality of different types of colors include red, green, and blue as the three primary colors of light (hereinafter simply referred to as “three primary colors”), and at least two of the plurality of primary colors A case where yellow (a combination of red and green) is included as a color obtained by combining primary colors will be described.
　液晶表示装置１内には、赤色を表示するＲ画素８、緑色を表示するＧ画素１０、青色を表示するＢ画素１２、および、黄色を表示するＹｅ画素１４がそれぞれ形成されている。これらの画素を組み合わせて用いることによって、所望のカラー画像を表示する。 In the liquid crystal display device 1, an R pixel 8 for displaying red, a G pixel 10 for displaying green, a B pixel 12 for displaying blue, and a Ye pixel 14 for displaying yellow are formed. By using these pixels in combination, a desired color image is displayed.
　このように、液晶表示装置１が、赤色、緑色、および青色の３原色をそれぞれ表示する画素のみならず、３原色以外の色である黄色を表示する画素を備えることによって、３原色を表示する画素のみを備える構成に比べて、それぞれの画素によって表示される色の混色により表現できる色の数を格段に増加させることができる。また、ライトブルー、イエロー、および、ゴールド等の色の主観的な美しさを格段に向上させることができる。 Thus, the liquid crystal display device 1 displays the three primary colors by including pixels that display not only the three primary colors of red, green, and blue, but also yellow that is a color other than the three primary colors. Compared to a configuration including only pixels, the number of colors that can be expressed by the color mixture of colors displayed by each pixel can be significantly increased. In addition, the subjective beauty of colors such as light blue, yellow, and gold can be significantly improved.
　（明画素および暗画素）
　Ｒ画素８、Ｇ画素１０、Ｂ画素１２、および、Ｙｅ画素１４は、いずれも、それぞれ液晶層に互いに異なる電圧を印加することができる２つ副画素（明画素および暗画素）を有している。Ｒ画素８は明画素８ａおよび暗画素８ｂを有し、Ｇ画素１０は明画素１０ａおよび暗画素１０ｂを有し、Ｂ画素１２は明画素１２ａおよび暗画素１２ｂを有し、Ｙｅ画素１４は明画素１４ａおよび暗画素１４ｂを有している。 (Bright and dark pixels)
Each of the R pixel 8, the G pixel 10, the B pixel 12, and the Ye pixel 14 has two sub-pixels (bright pixel and dark pixel) that can apply different voltages to the liquid crystal layer. Yes. The R pixel 8 has a bright pixel 8a and a dark pixel 8b, the G pixel 10 has a bright pixel 10a and a dark pixel 10b, the B pixel 12 has a bright pixel 12a and a dark pixel 12b, and the Ye pixel 14 has a bright pixel. It has a pixel 14a and a dark pixel 14b.
　各副画素は、いずれも、対向電極と、液晶層を介して当該対向電極に対向する副画素電極とによって形成される液晶容量を有している。さらに、副画素電極に電気的に接続された補助容量電極と、絶縁層と、当該絶縁層を介して補助容量電極と対向する補助容量対向電極とによって形成された、少なくとも１つの補助容量も有している。 Each sub-pixel has a liquid crystal capacitance formed by a counter electrode and a sub-pixel electrode facing the counter electrode via a liquid crystal layer. Further, there is at least one auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the subpixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode through the insulating layer. is doing.
　後述するように、各副画素の副画素電極にある階調に対応する表示電圧（画素電極電圧）が供給された後に、それぞれ対応する少なくとも１つの補助容量を介して、明画素の液晶容量に印加される電圧と、暗画素の液晶容量に印加される電圧との間には、一定の電圧差が発生する。これにより、ある階調において、明画素は暗画素よりも高い輝度を呈する。 As will be described later, after the display voltage (pixel electrode voltage) corresponding to the gray level on the subpixel electrode of each subpixel is supplied, the liquid crystal capacitor of the bright pixel is supplied via at least one auxiliary capacitor corresponding thereto. There is a certain voltage difference between the applied voltage and the voltage applied to the liquid crystal capacitance of the dark pixel. Thereby, in a certain gradation, a bright pixel exhibits higher luminance than a dark pixel.
　（液晶容量および補助容量）
　各画素の有する副画素は、液晶容量を有している。明画素は、液晶容量Ｃｌｃ１を有しており、暗画素は液晶容量Ｃｌｃ２を有している。 (Liquid crystal capacity and auxiliary capacity)
A sub-pixel included in each pixel has a liquid crystal capacitance. The bright pixel has a liquid crystal capacitance Clc1, and the dark pixel has a liquid crystal capacitance Clc2.
　より具体的には、図１に示すように、Ｒ画素８の明画素８ａは、液晶容量Ｃｌｃ１Ｒを有しており、暗画素８ｂは、液晶容量Ｃｌｃ２Ｒを有している。同様に、Ｇ画素１０の明画素１０ａは、液晶容量Ｃｌｃ１Ｇを有しており、暗画素１０ｂは、液晶容量Ｃｌｃ２Ｇを有しており、Ｂ画素１２の明画素１２ａは、液晶容量Ｃｌｃ１Ｂを有しており、暗画素１２ｂは、液晶容量Ｃｌｃ２Ｂを有しており、Ｙｅ画素１４の明画素１４ａは、液晶容量Ｃｌｃ１Ｙｅを有しており、暗画素１４ｂは、液晶容量Ｃｌｃ２Ｙｅを有している。 More specifically, as shown in FIG. 1, the bright pixel 8a of the R pixel 8 has a liquid crystal capacitance Clc1R, and the dark pixel 8b has a liquid crystal capacitance Clc2R. Similarly, the bright pixel 10a of the G pixel 10 has a liquid crystal capacitance Clc1G, the dark pixel 10b has a liquid crystal capacitance Clc2G, and the bright pixel 12a of the B pixel 12 has a liquid crystal capacitance Clc1B. The dark pixel 12b has a liquid crystal capacitance Clc2B, the bright pixel 14a of the Ye pixel 14 has a liquid crystal capacitance Clc1Ye, and the dark pixel 14b has a liquid crystal capacitance Clc2Ye.
　また、液晶容量Ｃｌｃ１には、電気的に並列に第１の補助容量Ｃｓ１が接続されており、液晶容量Ｃｌｃ２には、電気的に並列に第２の補助容量Ｃｓ２が接続されている。 The first auxiliary capacitor Cs1 is electrically connected in parallel to the liquid crystal capacitor Clc1, and the second auxiliary capacitor Cs2 is electrically connected in parallel to the liquid crystal capacitor Clc2.
　より具体的には、液晶容量Ｃｌｃ１Ｒには、電気的に並列に補助容量Ｃｓ１Ｒが接続され、液晶容量Ｃｌｃ２Ｒには、電気的に並列に補助容量Ｃｓ２Ｒが接続されている。同様に、液晶容量Ｃｌｃ１Ｇには、電気的に並列に補助容量Ｃｓ１Ｇが接続され、液晶容量Ｃｌｃ２Ｇには、電気的に並列に補助容量Ｃｓ２Ｇが接続されており、液晶容量Ｃｌｃ１Ｂには、電気的に並列に補助容量Ｃｓ１Ｂが接続され、液晶容量Ｃｌｃ２Ｂには、電気的に並列に補助容量Ｃｓ２Ｂが接続されており、液晶容量Ｃｌｃ１Ｙｅには、電気的に並列に補助容量Ｃｓ１Ｙｅが接続され、液晶容量Ｃｌｃ２Ｙｅには、電気的に並列に補助容量Ｃｓ２Ｙｅが接続されている。 More specifically, an auxiliary capacitor Cs1R is electrically connected in parallel to the liquid crystal capacitor Clc1R, and an auxiliary capacitor Cs2R is electrically connected in parallel to the liquid crystal capacitor Clc2R. Similarly, the auxiliary capacitor Cs1G is electrically connected in parallel to the liquid crystal capacitor Clc1G, the auxiliary capacitor Cs2G is electrically connected in parallel to the liquid crystal capacitor Clc2G, and the liquid crystal capacitor Clc1B is electrically connected to the liquid crystal capacitor Clc1B. The auxiliary capacitor Cs1B is connected in parallel, the auxiliary capacitor Cs2B is electrically connected in parallel to the liquid crystal capacitor Clc2B, the auxiliary capacitor Cs1Ye is electrically connected in parallel to the liquid crystal capacitor Clc1Ye, and the liquid crystal capacitor Clc2Ye is connected. Are connected in parallel with an auxiliary capacitor Cs2Ye.
　以下では、補助容量Ｃｓ１Ｒの容量値と補助容量Ｃｓ２Ｒの容量値とが等しい場合には、両者を共に補助容量ＣｓＲと称し、補助容量Ｃｓ１Ｇの容量値と補助容量Ｃｓ２Ｇの容量値とが等しい場合には、両者を共に補助容量ＣｓＧと称し、補助容量Ｃｓ１Ｂの容量値と補助容量Ｃｓ２Ｂの容量値とが等しい場合には、両者を共に補助容量ＣｓＢと称し、補助容量Ｃｓ１Ｙｅの容量値と補助容量Ｃｓ２Ｙｅの容量値とが等しい場合には、両者を共に補助容量ＣｓＹｅと称する。 Hereinafter, when the capacitance value of the auxiliary capacitor Cs1R and the capacitance value of the auxiliary capacitor Cs2R are equal, both are referred to as the auxiliary capacitor CsR, and when the capacitance value of the auxiliary capacitor Cs1G and the capacitance value of the auxiliary capacitor Cs2G are equal. Are both referred to as an auxiliary capacity CsG, and when the capacity value of the auxiliary capacity Cs1B and the capacity value of the auxiliary capacity Cs2B are equal, both are referred to as an auxiliary capacity CsB, and the capacity value of the auxiliary capacity Cs1Ye and the auxiliary capacity Cs2Ye Are equal to each other, they are both referred to as an auxiliary capacitor CsYe.
　（スイッチング素子）
　Ｒ画素８、Ｇ画素１０、Ｂ画素１２、およびＹｅ画素１４には、いずれも、ＴＦＴ１およびＴＦＴ２がそれぞれ形成されている。ＴＦＴ１は明画素に形成され、ＴＦＴ２は暗画素に形成される。各補助容量Ｃｓの補助容量電極は、それぞれ対応するＴＦＴ１またはＴＦＴ２のドレイン電極に接続されている。ＴＦＴ１およびＴＦＴ２のゲート電極は共通のゲートバスライン２ｌに接続されており、ＴＦＴ１およびＴＦＴ２のソース電極は共通のソースバスライン４に接続されている。すなわち、図１に示すように、Ｒ画素８のＴＦＴ１ＲおよびＴＦＴ２Ｒのソース電極は、ソースバスライン４ｍに接続されている。同様に、Ｇ画素１０のＴＦＴ１ＧおよびＴＦＴ２Ｇのソース電極は、ソースバスライン４（ｍ＋１）に接続されており、Ｂ画素１２のＴＦＴ１ＢおよびＴＦＴ２Ｂのソース電極は、ソースバスライン４（ｍ＋２）に接続されており、Ｙｅ画素１４のＴＦＴ１ＹｅおよびＴＦＴ２Ｙｅのソース電極は、ソースバスライン４（ｍ＋３）に接続されている。 (Switching element)
In each of the R pixel 8, the G pixel 10, the B pixel 12, and the Ye pixel 14, TFT1 and TFT2 are formed, respectively. TFT1 is formed in a bright pixel, and TFT2 is formed in a dark pixel. The auxiliary capacitance electrode of each auxiliary capacitance Cs is connected to the corresponding drain electrode of TFT1 or TFT2. The gate electrodes of TFT1 and TFT2 are connected to a common gate bus line 21, and the source electrodes of TFT1 and TFT2 are connected to a common source bus line 4. That is, as shown in FIG. 1, the source electrodes of the TFT 1R and TFT 2R of the R pixel 8 are connected to the source bus line 4m. Similarly, the source electrodes of the TFT 1G and TFT 2G of the G pixel 10 are connected to the source bus line 4 (m + 1), and the source electrodes of the TFT 1B and TFT 2B of the B pixel 12 are connected to the source bus line 4 (m + 2). The source electrodes of the TFT1Ye and TFT2Ye of the Ye pixel 14 are connected to the source bus line 4 (m + 3).
　ＴＦＴ１およびＴＦＴ２は、それぞれ、自身の備えるゲート電極にハイレベルのゲート信号が印加されているとき、導通状態（オン状態）となり、自身の備えるゲート電極にローレベルのゲート信号が印加されているとき、非導通状態（オフ状態、遮断状態）となる。 Each of TFT1 and TFT2 is in a conductive state (on state) when a high level gate signal is applied to its own gate electrode, and when a low level gate signal is applied to its own gate electrode. , It becomes a non-conduction state (off state, cutoff state).
　（ＣＳバスライン６）
　ゲートバスライン２およびソースバスライン４により画定された画素領域を横切るように、ＣＳバスライン６がゲートバスライン２に並列して延びている。各ＣＳバスライン６は、液晶表示装置１における同一行に形成されたＲ画素８、Ｇ画素１０、Ｂ画素１２、および、Ｙｅ画素１４に共通して設けられている。ＣＳバスライン６ｎは、補助容量Ｃｓ１Ｒ、補助容量Ｃｓ１Ｇ、補助容量Ｃｓ１Ｂ、および補助容量Ｃｓ１Ｙｅに接続されている。一方、ＣＳバスライン６（ｎ＋１）は、補助容量Ｃｓ２Ｒ、補助容量Ｃｓ２Ｇ、補助容量Ｃｓ２Ｂ、および、補助容量Ｃｓ２Ｙｅに接続されている。 (CS bus line 6)
A CS bus line 6 extends in parallel to the gate bus line 2 so as to cross a pixel region defined by the gate bus line 2 and the source bus line 4. Each CS bus line 6 is provided in common to the R pixel 8, the G pixel 10, the B pixel 12, and the Ye pixel 14 formed in the same row in the liquid crystal display device 1. The CS bus line 6n is connected to the auxiliary capacitor Cs1R, the auxiliary capacitor Cs1G, the auxiliary capacitor Cs1B, and the auxiliary capacitor Cs1Ye. On the other hand, the CS bus line 6 (n + 1) is connected to the auxiliary capacitor Cs2R, the auxiliary capacitor Cs2G, the auxiliary capacitor Cs2B, and the auxiliary capacitor Cs2Ye.
　（液晶表示装置１の動作）
　以下では、マルチ画素構造を有する液晶表示装置１における等価回路の駆動方法について図２（ａ）～図２（ｆ）を参照して説明する。なお、以下では、最初に、Ｒ画素８の駆動について説明を行い、その後、Ｇ画素１０、Ｂ画素１２、およびＹｅ画素１４の駆動について説明を行う。 (Operation of the liquid crystal display device 1)
Hereinafter, a driving method of an equivalent circuit in the liquid crystal display device 1 having a multi-pixel structure will be described with reference to FIGS. 2 (a) to 2 (f). In the following, driving of the R pixel 8 will be described first, and then driving of the G pixel 10, the B pixel 12, and the Ye pixel 14 will be described.
　また、一般には、各補助容量の値、および、各液晶容量の値は、それぞれに印加される電圧への依存性を有するが、本実施形態においては本質的な事項ではないため、以下の説明ではそのような依存性を無視する。ただし、この前提は、本実施形態を限定するものではなく、そのような依存性がある場合に対しても、同様に適用することができる。 In general, the value of each auxiliary capacitance and the value of each liquid crystal capacitance have a dependency on the voltage applied to each, but are not essential matters in the present embodiment. So ignore such dependencies. However, this premise does not limit the present embodiment, and can be similarly applied to a case where there is such dependency.
　図２は、液晶表示装置１を駆動する際の各電圧の波形およびタイミングを模式的に示したタイミングチャートである。 FIG. 2 is a timing chart schematically showing the waveform and timing of each voltage when the liquid crystal display device 1 is driven.
　図２（ａ）は、ソースドライバがソースバスライン４に供給するデータ信号の電圧波形Ｖｓを示しており、図２（ｂ）は、ＣＳドライバがＣＳバスライン６ｎに供給する補助容量駆動信号の電圧波形（すなわち、ＣＳバスライン６ｎの電圧波形）Ｖｃｓ１を示しており、図２（ｃ）はＣＳドライバがＣＳバスライン６（ｎ＋１）に供給する補助容量駆動信号の電圧波形（すなわち、ＣＳバスライン６（ｎ＋１）の電圧波形）Ｖｃｓ２を示しており、図２（ｄ）は、ゲートドライバがゲートバスライン２に供給するゲート信号の電圧波形Ｖｇを示しており、図２（ｅ）は、Ｒ画素８の備える明画素８ａの副画素電極の電圧波形Ｖｌｃ１Ｒを示しており、図２（ｆ）は、Ｒ画素８の備える暗画素８ｂの副画素電極の電圧波形Ｖｌｃ２Ｒを示している。また、図中の破線は、対向電極の電圧波形ＣＯＭＭＯＮ（Ｖｃｏｍ）を示している。 FIG. 2A shows a voltage waveform Vs of a data signal supplied from the source driver to the source bus line 4, and FIG. 2B shows an auxiliary capacitor drive signal supplied from the CS driver to the CS bus line 6n. FIG. 2C shows a voltage waveform (that is, the voltage waveform of the CS bus line 6n) Vcs1, and FIG. 2C shows a voltage waveform of the auxiliary capacitance drive signal (that is, the CS bus) that the CS driver supplies to the CS bus line 6 (n + 1). 2 (d) shows the voltage waveform Vg of the gate signal supplied to the gate bus line 2 by the gate driver, and FIG. 2 (e) shows the voltage waveform Vg of the line 6 (n + 1). The voltage waveform Vlc1R of the subpixel electrode of the bright pixel 8a included in the R pixel 8 is shown, and FIG. 2F shows the voltage waveform Vlc2R of the subpixel electrode of the dark pixel 8b included in the R pixel 8. That. Moreover, the broken line in the figure indicates the voltage waveform COMMON (Vcom) of the counter electrode.
　まず、時刻Ｔ１において、ゲート信号の電圧Ｖｇが、ＶｇＬ（ロー）からＶｇＨ（ハイ）に変化することにより、ＴＦＴ１とＴＦＴ２とが同時に導通状態（オン状態）となる。これに伴い、明画素８ａの副画素電極、および、暗画素８ｂの副画素電極に対し、ソースバスライン４を介してデータ信号の電圧が印加され、明画素８ａの副画素電極、および、暗画素８ｂの副画素電極の何れの電圧も、データ信号の電圧Ｖｓへと変化する。また、明画素８ａの補助容量Ｃｓ１Ｒ、および、暗画素８ｂの補助容量Ｃｓ２Ｒに対しても、ソースバスライン４を介してデータ信号の電圧が印加され、明画素８ａの補助容量電極、および、暗画素８ｂの補助容量電極の何れの電圧も、データ信号の電圧Ｖｓへと変化する。 First, at time T1, the voltage Vg of the gate signal changes from VgL (low) to VgH (high), so that TFT1 and TFT2 are simultaneously turned on (on state). Accordingly, the voltage of the data signal is applied to the sub-pixel electrode of the bright pixel 8a and the sub-pixel electrode of the dark pixel 8b via the source bus line 4, and the sub-pixel electrode of the bright pixel 8a and the dark pixel 8b Any voltage of the sub-pixel electrode of the pixel 8b changes to the voltage Vs of the data signal. The voltage of the data signal is also applied to the auxiliary capacitor Cs1R of the bright pixel 8a and the auxiliary capacitor Cs2R of the dark pixel 8b via the source bus line 4, and the auxiliary capacitor electrode of the bright pixel 8a and the dark capacitor 8s Any voltage of the auxiliary capacitance electrode of the pixel 8b changes to the voltage Vs of the data signal.
　ソースバスライン４を介して伝達されるデータ信号の電圧Ｖｓは当該画素において表示すべき階調に対応する表示電圧であり、ＴＦＴがオン状態の間（「選択期間」ということもある。）に、対応する画素に書き込まれる。 The voltage Vs of the data signal transmitted via the source bus line 4 is a display voltage corresponding to the gradation to be displayed in the pixel, and the TFT is in an on state (sometimes referred to as “selection period”). , The corresponding pixel is written.
　続いて、時刻Ｔ２において、ゲート信号の電圧ＶｇがＶｇＨからＶｇＬに変化することにより、ＴＦＴ１とＴＦＴ２とが同時に非導通状態（オフ状態）となる。これに伴い、明画素８ａの副画素電極、暗画素８ｂの副画素電極、明画素８ａの補助容量電極、および、暗画素８ｂの補助容量電極は、全てソースバスライン４と電気的に絶縁される（この状態にある期間を「非選択期間」ということがある。）。 Subsequently, at time T2, the voltage Vg of the gate signal changes from VgH to VgL, so that TFT1 and TFT2 are simultaneously turned off (off state). Accordingly, the sub-pixel electrode of the bright pixel 8a, the sub-pixel electrode of the dark pixel 8b, the auxiliary capacitance electrode of the bright pixel 8a, and the auxiliary capacitance electrode of the dark pixel 8b are all electrically insulated from the source bus line 4. (The period in this state may be referred to as “non-selection period”.)
　また、ＴＦＴがオン状態からオフ状態に切り替わった直後、ＴＦＴ１、ＴＦＴ２の有する寄生容量等の影響による引き込み現象のために、それぞれの副画素電極の電圧Ｖｌｃ１ＲおよびＶｌｃ２Ｒは概ね同一の電圧ΔＶｄだけ低下し、
　Ｖｌｃ１Ｒ＝Ｖｓ－ΔＶｄ　　　…（１ａ）
　Ｖｌｃ２Ｒ＝Ｖｓ－ΔＶｄ　　　…（１ｂ）
となる。また、このとき、それぞれのＣＳバスライン６の電圧Ｖｃｓ１、Ｖｃｓ２は、
　Ｖｃｓ１＝Ｖｃｏｍ－（１／２）Ｖａｄ　　　…（２ａ）
　Ｖｃｓ２＝Ｖｃｏｍ＋（１／２）Ｖａｄ　　　…（２ｂ）
である。すなわち、ここで例示するＣＳバスライン６に供給される補助容量駆動信号の電圧Ｖｃｓ１およびＶｃｓ２の波形は全幅がＶａｄで、位相が互いに逆相（１８０°異なる）である矩形波（デューティ比は１：１）である。 Immediately after the TFT is switched from the on state to the off state, the voltages Vlc1R and Vlc2R of the respective subpixel electrodes decrease by substantially the same voltage ΔVd due to a pull-in phenomenon due to the influence of the parasitic capacitances of the TFT1 and TFT2. ,
Vlc1R = Vs−ΔVd (1a)
Vlc2R = Vs−ΔVd (1b)
It becomes. At this time, the voltages Vcs1 and Vcs2 of the respective CS bus lines 6 are
Vcs1 = Vcom− (1/2) Vad (2a)
Vcs2 = Vcom + (1/2) Vad (2b)
It is. That is, the waveforms of the voltages Vcs1 and Vcs2 of the auxiliary capacitance drive signal supplied to the CS bus line 6 exemplified here are Vad with a total width of Vad and phases opposite to each other (180 ° different) (with a duty ratio of 1). : 1).
　続いて、時刻Ｔ３において、補助容量Ｃｓ１に接続されたＣＳバスライン６ｎの電圧Ｖｃｓ１がＶｃｏｍ－（１／２）ＶａｄからＶｃｏｍ＋（１／２）Ｖａｄに変化し、補助容量Ｃｓ２に接続されたＣＳバスライン６（ｎ＋１）の電圧Ｖｃｓ２がＶｃｏｍ＋（１／２）ＶａｄからＶｃｏｍ－（１／２）Ｖａｄに変化する。それに伴い、副画素８ａの備える副画素電極の電圧Ｖｌｃ１Ｒ、および、副画素８ｂの備える副画素電極の電圧Ｖｌｃ２Ｒは、
　Ｖｌｃ１Ｒ＝Ｖｓ－ΔＶｄ＋Ｋ１Ｒ×Ｖａｄ　　　…（３ａ）
　Ｖｌｃ２Ｒ＝Ｖｓ－ΔＶｄ－Ｋ２Ｒ×Ｖａｄ　　　…（３ｂ）
へ変化する。ここで、Ｋ１ＲおよびＫ２Ｒは、それぞれ、
　Ｋ１Ｒ＝Ｃｓ１Ｒ／（Ｃｌｃ１Ｒ＋Ｃｓ１Ｒ）　　　…（４ａ）
　Ｋ２Ｒ＝Ｃｓ２Ｒ／（Ｃｌｃ２Ｒ＋Ｃｓ２Ｒ）　　　…（４ｂ）
である。 Subsequently, at time T3, the voltage Vcs1 of the CS bus line 6n connected to the auxiliary capacitor Cs1 changes from Vcom− (1/2) Vad to Vcom + (1/2) Vad, and the CS connected to the auxiliary capacitor Cs2 The voltage Vcs2 of the bus line 6 (n + 1) changes from Vcom + (1/2) Vad to Vcom− (1/2) Vad. Accordingly, the voltage Vlc1R of the subpixel electrode included in the subpixel 8a and the voltage Vlc2R of the subpixel electrode included in the subpixel 8b are:
Vlc1R = Vs−ΔVd + K1R × Vad (3a)
Vlc2R = Vs−ΔVd−K2R × Vad (3b)
To change. Here, K1R and K2R are respectively
K1R = Cs1R / (Clc1R + Cs1R) (4a)
K2R = Cs2R / (Clc2R + Cs2R) (4b)
It is.
　続いて、時刻Ｔ４において、Ｖｃｓ１がＶｃｏｍ＋（１／２）ＶａｄからＶｃｏｍ－（１／２）Ｖａｄへ、Ｖｃｓ２がＶｃｏｍ－（１／２）ＶａｄからＶｃｏｍ＋（１／２）Ｖａｄへ変化し、Ｖｌｃ１Ｒ、Ｖｌｃ２Ｒもまた、数式（３ａ）および数式（３ｂ）によって表される値から、数式（１ａ）および（１ｂ）によってそれぞれ表される値へと変化する。 Subsequently, at time T4, Vcs1 changes from Vcom + (1/2) Vad to Vcom- (1/2) Vad, Vcs2 changes from Vcom- (1/2) Vad to Vcom + (1/2) Vad, and Vlc1R. , Vlc2R also changes from the values represented by the equations (3a) and (3b) to the values represented by the equations (1a) and (1b), respectively.
　続いて、時刻Ｔ５において、Ｖｃｓ１がＶｃｏｍ－（１／２）ＶａｄからＶｃｏｍ＋（１／２）Ｖａｄへ、Ｖｃｓ２がＶｃｏｍ＋（１／２）ＶａｄからＶｃｏｍ－（１／２）Ｖａｄへ変化し、Ｖｌｃ１Ｒ、Ｖｌｃ２Ｒもまた、数式（１ａ）および（１ｂ）によって表される値から、数式（３ａ）および数式（３ｂ）によってそれぞれ表される値へと変化する。 Subsequently, at time T5, Vcs1 changes from Vcom− (1/2) Vad to Vcom + (1/2) Vad, Vcs2 changes from Vcom + (1/2) Vad to Vcom− (1/2) Vad, and Vlc1R. , Vlc2R also changes from the values represented by the mathematical expressions (1a) and (1b) to the values represented by the mathematical expressions (3a) and (3b), respectively.
　上記Ｔ４およびＴ５の繰り返し間隔を、水平書き込み時間１Ｈの１倍とするか、２倍とするか、３倍とするかあるいはそれ以上とするかは液晶表示装置の駆動方法（極性反転方法等）または表示状態（ちらつき、表示のざらつき感等）を鑑みて適宜設定すればよい。この繰り返しは次に画素が書き換えられるとき、すなわちＴ１に等価な時間になるまで継続される。したがって、Ｖｌｃ１ＲおよびＶｌｃ２Ｒの実効的な値は、
　Ｖｌｃ１Ｒ＝Ｖｓ－ΔＶｄ＋Ｋ１Ｒ×（１／２）Ｖａｄ　　　…（５ａ）
　Ｖｌｃ２Ｒ＝Ｖｓ－ΔＶｄ－Ｋ２Ｒ×（１／２）Ｖａｄ　　　…（５ｂ）
となる。 The method for driving the liquid crystal display device (polarity inversion method, etc.) determines whether the repetition interval of T4 and T5 is 1 time, 2 times, 3 times, or more than the horizontal writing time 1H. Alternatively, it may be set as appropriate in view of the display state (flickering, display roughness, etc.). This repetition is continued until the pixel is next rewritten, that is, until a time equivalent to T1 is reached. Therefore, the effective values of Vlc1R and Vlc2R are
Vlc1R = Vs−ΔVd + K1R × (1/2) Vad (5a)
Vlc2R = Vs−ΔVd−K2R × (1/2) Vad (5b)
It becomes.
　よって、明画素８ａおよび暗画素８ｂのそれぞれの液晶層に印加される実効電圧Ｖ１ＲおよびＶ２Ｒは、
　Ｖ１Ｒ＝Ｖｌｃ１Ｒ－Ｖｃｏｍ　　　…（６ａ）
　Ｖ２Ｒ＝Ｖｌｃ２Ｒ－Ｖｃｏｍ　　　…（６ｂ）
すなわち、
　Ｖ１Ｒ＝Ｖｓ－ΔＶｄ＋Ｋ１Ｒ×（１／２）Ｖａｄ－Ｖｃｏｍ　　　…（７ａ）
　Ｖ２Ｒ＝Ｖｓ－ΔＶｄ－Ｋ２Ｒ×（１／２）Ｖａｄ－Ｖｃｏｍ　　　…（７ｂ）
となる。 Therefore, the effective voltages V1R and V2R applied to the respective liquid crystal layers of the bright pixel 8a and the dark pixel 8b are:
V1R = Vlc1R-Vcom (6a)
V2R = Vlc2R−Vcom (6b)
That is,
V1R = Vs−ΔVd + K1R × (1/2) Vad−Vcom (7a)
V2R = Vs−ΔVd−K2R × (1/2) Vad−Vcom (7b)
It becomes.
　したがって、Ｒ画素８の備える明画素８ａおよび暗画素８ｂのぞれぞれの液晶層に印加される実効電圧の差（電位差）ΔＶ１２Ｒ（＝Ｖ１Ｒ－Ｖ２Ｒ、Ｒ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｒ＝（１／２）×（Ｋ１Ｒ＋Ｋ２Ｒ）×Ｖａｄ　　　…（８）
と表される。ここで、Ｋ１ＲおよびＫ２Ｒは、それぞれ、数式（４ａ）および（４ｂ）によって表される。 Therefore, the effective voltage difference (potential difference) ΔV12R (= V1R−V2R, which is applied to the liquid crystal layer of each of the bright pixel 8a and the dark pixel 8b included in the R pixel 8 may be “ΔVα” regarding the R pixel. .)
ΔV12R = (1/2) × (K1R + K2R) × Vad (8)
It is expressed. Here, K1R and K2R are represented by mathematical formulas (4a) and (4b), respectively.
　なお、液晶容量Ｃｌｃ１Ｒに対する補助容量Ｃｓ１Ｒの比（すなわち、Ｃｓ１Ｒ／Ｃｌｃ１Ｒ）と、液晶容量Ｃｌｃ２Ｒに対する補助容量Ｃｓ２Ｒの比（すなわち、Ｃｓ２Ｒ／Ｃｌｃ２Ｒ）とが互いに等しい場合には、Ｋ１ＲおよびＫ２Ｒは、
　Ｋ１Ｒ＝Ｋ２Ｒ＝ＤＲ／（ＤＲ＋１）
を満たす。ここで、ＤＲは、Ｒ画素の各副画素における液晶容量に対する補助容量の比を表しており、
　ＤＲ＝Ｃｓ１Ｒ／Ｃｌｃ１Ｒ＝Ｃｓ２Ｒ／Ｃｌｃ２Ｒ　　　…（９）
によって定義される。また、このような場合、ΔＶ１２Ｒは、
　ΔＶ１２Ｒ＝ＫＲ×Ｖａｄ　　　…（８’）
と表される。ここで、ＫＲ＝ＤＲ／（ＤＲ＋１）である。 When the ratio of the auxiliary capacity Cs1R to the liquid crystal capacity Clc1R (that is, Cs1R / Clc1R) and the ratio of the auxiliary capacity Cs2R to the liquid crystal capacity Clc2R (that is, Cs2R / Clc2R) are equal to each other, K1R and K2R are
K1R = K2R = DR / (DR + 1)
Meet. Here, DR represents the ratio of the auxiliary capacitance to the liquid crystal capacitance in each sub-pixel of the R pixel,
DR = Cs1R / Clc1R = Cs2R / Clc2R (9)
Defined by In such a case, ΔV12R is
ΔV12R = KR × Vad (8 ′)
It is expressed. Here, KR = DR / (DR + 1).
　このように、明画素における液晶容量に対する補助容量の比と暗画素における液晶容量に対する補助容量の比（以下、「容量比」と呼ぶこともある）とが互いに等しい場合には、明画素および暗画素のぞれぞれの液晶層に印加される実効電圧の差は、当該容量比によって特徴付けることができる。 As described above, when the ratio of the auxiliary capacity to the liquid crystal capacity in the bright pixel and the ratio of the auxiliary capacity to the liquid crystal capacity in the dark pixel (hereinafter also referred to as “capacitance ratio”) are equal to each other, The difference in effective voltage applied to each liquid crystal layer of each pixel can be characterized by the capacitance ratio.
　Ｇ画素１０に関しても、同様の駆動が行われ、Ｇ画素１０の備える明画素１０ａおよび暗画素１０ｂのぞれぞれの液晶層に印加される実効電圧の差ΔＶ１２Ｇ（Ｇ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｇ＝（１／２）×（Ｋ１Ｇ＋Ｋ２Ｇ）×Ｖａｄ　　　…（１０）
と表される。ここで、Ｋ１ＧおよびＫ２Ｇは、
　Ｋ１Ｇ＝Ｃｓ１Ｇ／（Ｃｌｃ１Ｇ＋Ｃｓ１Ｇ）　　　…（１１ａ）
　Ｋ２Ｇ＝Ｃｓ２Ｇ／（Ｃｌｃ２Ｇ＋Ｃｓ２Ｇ）　　　…（１１ｂ）
である。 The G pixel 10 is also driven in the same manner, and the difference ΔV12G (referred to as “ΔVα” relating to the G pixel) between the effective voltages applied to the liquid crystal layers of the bright pixel 10a and the dark pixel 10b included in the G pixel 10. Sometimes)
ΔV12G = (1/2) × (K1G + K2G) × Vad (10)
It is expressed. Here, K1G and K2G are
K1G = Cs1G / (Clc1G + Cs1G) (11a)
K2G = Cs2G / (Clc2G + Cs2G) (11b)
It is.
　また、明画素１０ａにおける容量比と、暗画素１０ｂにおける容量比とが互いに等しい場合には、ΔＶ１２Ｇは、
　ΔＶ１２Ｇ＝ＫＧ×Ｖａｄ　　　…（１０’）
と表される。ここで、ＫＧ＝ＤＧ／（ＤＧ＋１）であり、
　ＤＧ＝Ｃｓ１Ｇ／Ｃｌｃ１Ｇ＝Ｃｓ２Ｇ／Ｃｌｃ２Ｇ　　　…（１２）
である。 When the capacitance ratio in the bright pixel 10a and the capacitance ratio in the dark pixel 10b are equal to each other, ΔV12G is
ΔV12G = KG × Vad (10 ′)
It is expressed. Here, KG = DG / (DG + 1),
DG = Cs1G / Clc1G = Cs2G / Clc2G (12)
It is.
　また、Ｂ画素１２に関しても、同様の駆動が行われ、Ｂ画素１２の備える明画素１２ａおよび暗画素１２ｂのぞれぞれの液晶層に印加される実効電圧の差ΔＶ１２Ｂ（Ｂ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｂ＝（１／２）×（Ｋ１Ｂ＋Ｋ２Ｂ）×Ｖａｄ　　　…（１３）
と表される。ここで、Ｋ１ＢおよびＫ２Ｂは、
　Ｋ１Ｂ＝Ｃｓ１Ｂ／（Ｃｌｃ１Ｂ＋Ｃｓ１Ｂ）　　　…（１４ａ）
　Ｋ２Ｂ＝Ｃｓ２Ｂ／（Ｃｌｃ２Ｂ＋Ｃｓ２Ｂ）　　　…（１４ｂ）
である。 The B pixel 12 is also driven in the same manner, and the difference ΔV12B in effective voltage applied to the liquid crystal layer of each of the bright pixel 12a and the dark pixel 12b included in the B pixel 12 (“ΔVα relating to the B pixel”). ”).
ΔV12B = (1/2) × (K1B + K2B) × Vad (13)
It is expressed. Here, K1B and K2B are
K1B = Cs1B / (Clc1B + Cs1B) (14a)
K2B = Cs2B / (Clc2B + Cs2B) (14b)
It is.
　また、明画素１２ａにおける容量比と、暗画素１２ｂにおける容量比とが互いに等しい場合には、ΔＶ１２Ｂは、
　ΔＶ１２Ｂ＝ＫＢ×Ｖａｄ　　　…（１３’）
と表される。ここで、ＫＢ＝ＤＢ／（ＤＢ＋１）であり、
　ＤＢ＝Ｃｓ１Ｂ／Ｃｌｃ１Ｂ＝Ｃｓ２Ｂ／Ｃｌｃ２Ｂ　　　…（１５）
である。 When the capacitance ratio in the bright pixel 12a and the capacitance ratio in the dark pixel 12b are equal to each other, ΔV12B is
ΔV12B = KB × Vad (13 ′)
It is expressed. Here, KB = DB / (DB + 1),
DB = Cs1B / Clc1B = Cs2B / Clc2B (15)
It is.
　また、Ｙｅ画素１４に関しても、同様の駆動が行われ、Ｙｅ画素１４の備える明画素１４ａおよび暗画素１４ｂのぞれぞれの液晶層に印加される実効電圧の差ΔＶ１２Ｙｅ（Ｙｅ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｙｅ＝（１／２）×（Ｋ１Ｙｅ＋Ｋ２Ｙｅ）×Ｖａｄ　　　…（１６）
と表される。ここで、Ｋ１ＹｅおよびＫ２Ｙｅは、
　Ｋ１Ｙｅ＝Ｃｓ１Ｙｅ／（Ｃｌｃ１Ｙｅ＋Ｃｓ１Ｙｅ）　　　…（１７ａ）
　Ｋ２Ｙｅ＝Ｃｓ２Ｙｅ／（Ｃｌｃ２Ｙｅ＋Ｃｓ２Ｙｅ）　　　…（１７ｂ）
である。 The Ye pixel 14 is also driven in the same manner, and the difference between the effective voltages applied to the liquid crystal layers of the bright pixel 14a and the dark pixel 14b included in the Ye pixel 14 ΔV12Ye (“ΔVα relating to the Ye pixel”). ”).
ΔV12Ye = (1/2) × (K1Ye + K2Ye) × Vad (16)
It is expressed. Here, K1Ye and K2Ye are
K1Ye = Cs1Ye / (Clc1Ye + Cs1Ye) (17a)
K2Ye = Cs2Ye / (Clc2Ye + Cs2Ye) (17b)
It is.
　また、明画素１４ａにおける容量比と、暗画素１４ｂにおける容量比とが互いに等しい場合には、ΔＶ１２Ｙｅは、
　ΔＶ１２Ｙｅ＝ＫＹｅ×Ｖａｄ　　　…（１６’）
と表される。ここで、ＫＹｅ＝ＤＹｅ／（ＤＹｅ＋１）であり、
　ＤＹｅ＝Ｃｓ１Ｙｅ／Ｃｌｃ１Ｙｅ＝Ｃｓ２Ｙｅ／Ｃｌｃ２Ｙｅ　　　…（１８）
である。 Further, when the capacitance ratio in the bright pixel 14a and the capacitance ratio in the dark pixel 14b are equal to each other, ΔV12Ye is
ΔV12Ye = KYe × Vad (16 ′)
It is expressed. Here, KYe = DYe / (DYe + 1),
DYe = Cs1Ye / Clc1Ye = Cs2Ye / Clc2Ye (18)
It is.
　以上のように、各画素の備える各副画素における液晶容量および補助容量の値を適宜変更することにより、各画素の備える副画素のそれぞれの液晶層に印加される実効電圧の差を所望の値に設定することができる。 As described above, by appropriately changing the value of the liquid crystal capacitance and the auxiliary capacitance in each subpixel included in each pixel, the difference in effective voltage applied to each liquid crystal layer of the subpixel included in each pixel is set to a desired value. Can be set to
　また、副画素のそれぞれにおける容量比が互いに等しい画素においては、当該容量比の値を適否変更することにより、当該画素の備える副画素のそれぞれの液晶層に印加される実効電圧の差を所望の値に設定することができる。 In addition, in the pixels having the same capacitance ratio in each of the sub-pixels, the difference in effective voltage applied to the respective liquid crystal layers of the sub-pixels included in the pixel can be changed by appropriately changing the value of the capacitance ratio. Can be set to a value.
　また、各画素の備える各副画素における液晶容量および補助容量の値、または、各画素における容量比は、表示画像に生じ得る色ずれの現象を低減するように定めることができる。ここで、色ずれの現象とは、表示画面を正面から観察した場合に比べて、斜めから観察したときでは表示画像の色調が異なって見えてしまう現象のことである。 Also, the values of the liquid crystal capacitance and the auxiliary capacitance in each subpixel included in each pixel, or the capacitance ratio in each pixel can be determined so as to reduce the phenomenon of color misregistration that may occur in the display image. Here, the phenomenon of color misregistration is a phenomenon in which the color tone of a display image looks different when observed obliquely compared to when the display screen is observed from the front.
　以下では、表示画像に生じ得る色ずれの現象を低減するような、各画素の備える各副画素における液晶容量および補助容量の値、または、各画素における容量比の具体的な値についての説明を行うが、それに先立ち、従来の液晶表示装置において発生する色ずれの現象について説明を行う。 In the following description, the values of the liquid crystal capacitance and the auxiliary capacitance in each sub-pixel included in each pixel, or specific values of the capacitance ratio in each pixel, which reduce the phenomenon of color misregistration that may occur in the display image, will be described. Prior to that, the phenomenon of color misregistration occurring in the conventional liquid crystal display device will be described.
　（ＸＹＺ表色系）
　まず、色を定量的に表す体系である表色系について説明する。代表的な表色系として、赤（Ｒ）、緑（Ｇ）、および青（Ｂ）の三原色を用いたＲＧＢ表色系がある。しかし、ＲＧＢ表色系では知覚可能な色の全てを必ずしも完全に表色できるわけではなく、例えばレーザー光などに見られる単一波長の色はＲＧＢ表色系の外側にある。ＲＧＢ値の係数に負の値を許可すれば、ＲＧＢ表色系においても任意の色を表色できるようになるが、取り扱いに不便さが生じる。そこで一般には、ＲＧＢ表色系を改善したＸＹＺ表色系が用いられる。 (XYZ color system)
First, a color system that is a system for quantitatively expressing colors will be described. As a representative color system, there is an RGB color system using three primary colors of red (R), green (G), and blue (B). However, in the RGB color system, not all perceptible colors can be expressed completely, and a single wavelength color found in, for example, laser light is outside the RGB color system. If a negative value is permitted for the coefficient of the RGB value, an arbitrary color can be represented even in the RGB color system, but inconvenience arises in handling. In general, therefore, an XYZ color system in which the RGB color system is improved is used.
　ＸＹＺ表色系においては、三刺激値（Ｘ値、Ｙ値、Ｚ値）の組み合わせによって、所望の色を表色する。新たな刺激値であるＸ値、Ｙ値、Ｚ値は、元のＲ値、Ｇ値、Ｂ値を相互に足し合わせることによって得られる。これらの三刺激値を組み合わせれば、特定のスペクトルの色も、スペクトルの光の混合光も、さらに物体の色もすべて表色することが可能になる。 In the XYZ color system, a desired color is represented by a combination of tristimulus values (X value, Y value, Z value). X values, Y values, and Z values that are new stimulus values are obtained by adding the original R value, G value, and B value to each other. By combining these tristimulus values, it is possible to display all colors of a specific spectrum, mixed light of spectra, and even the color of an object.
　Ｘ値、Ｙ値、Ｚ値のうち、Ｙ値は明るさの刺激に対応している。すなわち、Ｙ値は明度の代表値として用いることが可能である。また、Ｘ値は主に赤色を代表する刺激値であるが、青色の波長領域の色刺激も一定量含んでいる。Ｚ値は、主として青色を代表する色刺激である。 Ｙ Among X value, Y value, and Z value, Y value corresponds to brightness stimulus. That is, the Y value can be used as a representative value of brightness. The X value is a stimulus value mainly representing red, but also contains a certain amount of color stimulus in the blue wavelength region. The Z value is a color stimulus mainly representing blue.
　また、本実施形態のように、各画素が表示する赤色、緑色、青色、および黄色の混色によって表現される色も、上記ＸＹＺ表色系を用いて表現することができる。また、Ｙｅ画素１４が表示する黄色成分は、主に、上記ＸＹＺ表色系におけるＸ値およびＹ値に寄与する。 Further, as in the present embodiment, colors expressed by a mixed color of red, green, blue, and yellow displayed by each pixel can also be expressed using the XYZ color system. The yellow component displayed by the Ye pixel 14 mainly contributes to the X value and the Y value in the XYZ color system.
　（正面からの見え方）
　通常、液晶表示装置においては、正面視角（０度方向）において表示画面の色度が一定になるように調整されている。図３は、比較例に係る液晶表示装置の、正面視角における、階調と三刺激値（Ｘ値、Ｙ値、Ｚ値）との関係（特性）を示す図である。 (View from the front)
Normally, in a liquid crystal display device, the chromaticity of the display screen is adjusted to be constant at the front viewing angle (0 degree direction). FIG. 3 is a diagram illustrating a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device according to the comparative example.
　ここで、当該比較例に係る液晶表示装置は、ＶＡモードの液晶表示装置であり、本実施形態に係る液晶表示装置１と同様の画素構造を有している。また、当該比較例に係る液晶表示装置におけるＲ画素８、Ｇ画素１０、および、Ｙｅ画素１４の各画素の備える副画素のそれぞれにおける容量比は、画素ごとに互いに等しく設定されており、数式（９）、（１２）、（１８）によって表される各画素における容量比ＤＲ、ＤＧ、およびＤＹｅは、
　ＤＲ＝ＤＧ＝ＤＹｅ＝０．６
を満たしている。また、当該比較例に係る液晶表示装置においては、ＣＳバスライン６に供給される補助容量駆動信号の電圧波形の振幅は１．９Ｖであり、全幅Ｖａｄ＝３．８Ｖである。 Here, the liquid crystal display device according to the comparative example is a VA mode liquid crystal display device, and has the same pixel structure as the liquid crystal display device 1 according to the present embodiment. In addition, the capacitance ratios of the sub-pixels included in each of the R pixel 8, the G pixel 10, and the Ye pixel 14 in the liquid crystal display device according to the comparative example are set to be equal to each other. 9), (12), capacitance ratios DR, DG, and DYe in each pixel represented by (18) are
DR = DG = DYe = 0.6
Meet. Further, in the liquid crystal display device according to the comparative example, the amplitude of the voltage waveform of the auxiliary capacitance drive signal supplied to the CS bus line 6 is 1.9V, and the full width Vad = 3.8V.
　したがって、当該比較例に係る液晶表示装置の備える各副画素の液晶層に印加される実効電圧の差は、
　ΔＶ１２Ｒ＝ΔＶ１２Ｇ＝ΔＶ１２Ｙｅ＝（３／８）×Ｖａｄ＝（３／８）×３．８（Ｖ）
である。 Therefore, the difference in effective voltage applied to the liquid crystal layer of each subpixel included in the liquid crystal display device according to the comparative example is
ΔV12R = ΔV12G = ΔV12Ye = (3/8) × Vad = (3/8) × 3.8 (V)
It is.
　図３に示すように、正面視角においては、階調とＸ値、Ｙ値、Ｚ値との関係を示すグラフは、いずれも一定のγ（ガンマ）値を有する曲線となっている。したがって、当該比較例に係る液晶表示装置の表示画面を正面から観察した場合は、色ずれの現象は発生しない。 As shown in FIG. 3, at the front viewing angle, the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant γ (gamma) value. Therefore, when the display screen of the liquid crystal display device according to the comparative example is observed from the front, the phenomenon of color misregistration does not occur.
　（斜め方向からの見え方）
　しかし、ＶＡモードの液晶表示装置は、液晶層複屈折率効果を利用しており、液晶層のリタデーションが波長分散を持つため、光の波長によって透過率が変わる。また、液晶層のリタデーションは正面視角よりも斜め視角において見かけ上大きくなるので、斜め視角では透過率変動の光波長依存性が正面視角よりも増加する。この結果、正面から画面を観察した場合とは異なり、斜め方向から画面を観察した場合のγ値（より具体的には、後述するｌｏｃａｌγの値）は一定ではなくなるため、斜め方向において、色ずれの現象が発生する。また、色ずれの現象は、ＶＡモードの液晶表示装置にのみ生じるものではなく、例えば、ＴＮモードの液晶表示装置においても発生する。 (View from an oblique direction)
However, since the VA mode liquid crystal display device uses the birefringence effect of the liquid crystal layer and the retardation of the liquid crystal layer has wavelength dispersion, the transmittance varies depending on the wavelength of light. In addition, since the retardation of the liquid crystal layer is apparently larger at an oblique viewing angle than at the front viewing angle, the dependence of the transmittance variation on the light wavelength is greater than the front viewing angle at the oblique viewing angle. As a result, unlike the case where the screen is observed from the front, the γ value (more specifically, the value of local γ described later) when the screen is observed from the oblique direction is not constant. The phenomenon occurs. Further, the color shift phenomenon does not occur only in the VA mode liquid crystal display device, but also occurs in, for example, the TN mode liquid crystal display device.
　図４は、比較例に係る液晶表示装置の、斜め視角（より具体的には極角６０度）における階調－ＸＹＺ値特性を示す図である。 FIG. 4 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device according to the comparative example.
　図４に示すように、極角６０度においては、中間調において、Ｘ値およびＹ値がほぼ同じ階調（略１１０階調）にて立ち上がっている。すなわち、極角６０度においては、Ｘ値およびＹ値を示すグラフの傾きが、双方とも、略１１０階調にて変化し、略１１０階調以下における傾きよりも、略１１０階調以上略１５０階調以下における傾きの方が大きくなっている。また、Ｘ値を示すグラフ、および、Ｙ値を示すグラフ共に、１２０～１３０階調付近から、なだらかな傾きへと転じている。このようなＸ値およびＹ値を示すグラフのプロファイルは、特に略１００階調～略１５０階調の範囲において、Ｘ値およびＹ値のそれぞれについてのγ値が大きく変化していることを示している。 As shown in FIG. 4, at the polar angle of 60 degrees, the X value and the Y value rise at substantially the same gradation (approximately 110 gradations) in the halftone. That is, at the polar angle of 60 degrees, the slopes of the graphs indicating the X value and the Y value both change at about 110 gradations, and are about 110 gradations or more and about 150 than the inclinations at about 110 gradations or less. The slope below the gradation is larger. In addition, both the graph showing the X value and the graph showing the Y value have turned from the vicinity of 120 to 130 gradations to a gentle slope. Such a profile of the graph showing the X value and the Y value shows that the γ value for each of the X value and the Y value varies greatly, particularly in the range of about 100 gradations to about 150 gradations. Yes.
　このように、極角６０度においては、特に中間調において、Ｘ値およびＹ値を示すグラフの曲線が、γ値が一定である理想曲線から大きく外れるものとなるため、色ずれの現象が生じてしまう。また、このような、階調－ＸＹＺ値特性は、極角６０度に限られるものではなく、その他の極角によって規定される斜め視角においても同様である。したがって、比較例に係る液晶表示装置においては、一般に斜め視角において、中間調における色ずれの現象が生じてしまう。 In this way, at the polar angle of 60 degrees, particularly in the halftone, the curve of the graph showing the X value and the Y value deviates greatly from the ideal curve having a constant γ value, so that a color shift phenomenon occurs. End up. Further, such gradation-XYZ value characteristics are not limited to the polar angle of 60 degrees, and the same applies to oblique viewing angles defined by other polar angles. Therefore, in the liquid crystal display device according to the comparative example, a color misregistration phenomenon occurs in a halftone generally at an oblique viewing angle.
　以下では、当該比較例に係る液晶表示装置におけるＸ値およびＹ値のそれぞれについてのγ値（ｌｏｃａｌγの値）の特性を、図５を参照してより詳しく説明する。 Hereinafter, the characteristics of the γ value (local γ value) for each of the X value and the Y value in the liquid crystal display device according to the comparative example will be described in more detail with reference to FIG.
　図５は、比較例に係る液晶表示装置の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。ここで、ｌｏｃａｌγとは、γ値の局所的な傾きを示す指標である。 FIG. 5 is a diagram showing the gradation-local γ characteristics at a polar angle of 60 degrees of the liquid crystal display device according to the comparative example. Here, local γ is an index indicating a local gradient of the γ value.
　ここで、表示画面の法線方向に対して所定の角度から測定した光学特性における最大輝度をＴとし、前記所定の角度と同方向からの、階調値ａに基づく輝度をｔａ、階調値ｂ（ａとｂとは異なる値）に基づく輝度をｔｂとし、前記最大輝度Ｔ に対する前記輝度ｔａ及び前記輝度ｔｂのそれぞれの輝度比をＴａ及びＴｂとすると、ｌｏｃａｌγは、
　ｌｏｃａｌγ＝（ｌｏｇ（Ｔａ）－ｌｏｇ（Ｔｂ））／（ｌｏｇ（ａ）－ｌｏｇ（ｂ））　　　…（Ａ１）
によって定義される。 Here, T is the maximum luminance in the optical characteristics measured from a predetermined angle with respect to the normal direction of the display screen, and ta is the luminance based on the gradation value a from the same direction as the predetermined angle. When the luminance based on b (a value different from a and b) is tb and the luminance ratio of the luminance ta and the luminance tb to the maximum luminance T 1 is Ta and Tb, local γ is
localγ = (log (Ta) −log (Tb)) / (log (a) −log (b)) (A1)
Defined by
　図５に示すように、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、略１００階調以下において、互いに略等しく、また、略１００階調において、共に急峻な立ち上がりを示している。Ｘ値に関するｌｏｃａｌγは、略１００階調から略１２０階調までの区間において、略０．９増加し、Ｙ値に関するｌｏｃａｌγは、略１００階調から略１２０階調までの区間において、略１．１増加している。また、Ｙ値のｌｏｃａｌγの中間調（３２階調から１９２階調）における標準偏差σは、σ＝０．３８７となっている。 As shown in FIG. 5, the local γ value related to the X value and the local γ value related to the Y value are substantially equal to each other at about 100 gradations or less, and both show steep rises at about 100 gradations. Yes. The local γ related to the X value increases by about 0.9 in the section from about 100 gradations to about 120 gradations, and the local γ related to the Y value is about 1. in the section from about 100 gradations to about 120 gradations. 1 increase. In addition, the standard deviation σ in the halftone (32 gradations to 192 gradations) of the local γ of the Y value is σ = 0.387.
　色ずれが生じないようにするためには、ｌｏｃａｌγの値は、斜め視野角においても一定であることが望ましい。これは、正面視野角において、ｌｏｃａｌγの値が一定となるように調整されているためである。しかしながら、当該比較例に係る液晶表示装置においては、図５から明らかなように、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、特に略１００階調から略１５０階調において、大きく変化している。 In order to prevent color misregistration, the value of local γ is desirably constant even at an oblique viewing angle. This is because the value of local γ is adjusted to be constant at the front viewing angle. However, in the liquid crystal display device according to the comparative example, as is apparent from FIG. 5, the local γ value related to the X value and the local γ value related to the Y value are particularly in the range from about 100 to about 150 gradations. It has changed greatly.
　したがって、当該比較例に係る液晶表示装置においては、斜め視角において、中間調における色ずれが発生してしまう。 Therefore, in the liquid crystal display device according to the comparative example, a color shift in halftone occurs at an oblique viewing angle.
　また、ｌｏｃａｌγの標準偏差σは、色ずれの大きさを示す指標として用いることもできる。これは、標準偏差σが大きいことは、ｌｏｃａｌγの階調毎の変化が大きいことに対応し、標準偏差σが小さいことは、ｌｏｃａｌγの階調毎の変化が小さいこと、すなわち、ｌｏｃａｌγが一定に近いことに対応するためである。したがって、例えば、上記ｌｏｃａｌγの標準偏差σの値がより小さくなるように、各画素における補助容量および液晶容量の値、または、各画素における容量比を最適化することができれば、色ずれの現象を低減することができる。 Also, the standard deviation σ of local γ can be used as an index indicating the magnitude of color shift. This means that a large standard deviation σ corresponds to a large change in local γ for each gradation, and a small standard deviation σ means a small change in local γ for each gradation, that is, local γ is constant. This is to cope with closeness. Therefore, for example, if the value of the auxiliary capacitance and the liquid crystal capacitance in each pixel or the capacitance ratio in each pixel can be optimized so that the value of the standard deviation σ of the local γ becomes smaller, the phenomenon of color shift can be reduced. Can be reduced.
　（実施形態に係る液晶表示装置１における容量比の最適化）
　以下では、色ずれの現象を低減するために最適化された、本実施形態に係る液晶表示装置１の表示パネルが備える各画素における容量比について説明する。 (Optimization of capacity ratio in the liquid crystal display device 1 according to the embodiment)
Hereinafter, the capacitance ratio in each pixel included in the display panel of the liquid crystal display device 1 according to the present embodiment optimized for reducing the phenomenon of color misregistration will be described.
　本実施形態に係る液晶表示装置１の表示パネルにおいては、Ｒ画素８、Ｇ画素１０、および、Ｙｅ画素１４の各画素の備える副画素のそれぞれにおける容量比が、画素ごとに互いに等しく設定されており、さらに、数式（９）、（１２）、（１８）によって表される各画素における容量比ＤＲ、ＤＧ、およびＤＹｅは、
　ＤＲ＝ＤＧ＝０．６
　ＤＹｅ＝０．２
を満たしている。また、本実施形態に係る液晶表示装置１においては、ＣＳバスライン６に供給される補助容量駆動信号の電圧波形の振幅は１．９Ｖであり、全幅Ｖａｄ＝３．８Ｖである。 In the display panel of the liquid crystal display device 1 according to the present embodiment, the capacitance ratios of the sub-pixels included in each of the R pixel 8, the G pixel 10, and the Ye pixel 14 are set to be equal to each other. Furthermore, the capacitance ratios DR, DG, and DYe in each pixel represented by the equations (9), (12), and (18) are
DR = DG = 0.6
DYe = 0.2
Meet. Further, in the liquid crystal display device 1 according to the present embodiment, the amplitude of the voltage waveform of the auxiliary capacitance driving signal supplied to the CS bus line 6 is 1.9 V, and the full width Vad is 3.8 V.
　したがって、本実施形態に係る液晶表示装置１の備える各副画素の液晶層に印加される実効電圧の差は、
　ΔＶ１２Ｒ＝ΔＶ１２Ｇ＝（３／８）×Ｖａｄ＝（３／８）×３．８（Ｖ）
　ΔＶ１２Ｙｅ＝（１／６）×Ｖａｄ＝（１／６）×３．８（Ｖ）
である。 Therefore, the difference in effective voltage applied to the liquid crystal layer of each subpixel included in the liquid crystal display device 1 according to this embodiment is
ΔV12R = ΔV12G = (3/8) × Vad = (3/8) × 3.8 (V)
ΔV12Ye = (1/6) × Vad = (1/6) × 3.8 (V)
It is.
　上記のように、容量比ＤＹｅが、容量比ＤＲおよび容量比ＤＧに比べて小さいため、Ｙｅ画素１４の備える各副画素の液晶層に印加される実効電圧の差ΔＶ１２Ｙｅは、Ｒ画素８およびＧ画素１０のそれぞれ備える各副画素の液晶層に印加される実効電圧の差ΔＶ１２ＲおよびΔＶ１２Ｇに比べて、小さい。 As described above, since the capacitance ratio DYe is smaller than the capacitance ratio DR and the capacitance ratio DG, the difference ΔV12Ye between the effective voltages applied to the liquid crystal layers of the sub-pixels included in the Ye pixel 14 is the R pixel 8 and G It is smaller than the difference ΔV12R and ΔV12G in effective voltage applied to the liquid crystal layer of each subpixel included in each pixel 10.
　このように、Ｙｅ画素１４における実効電圧の差ΔＶ１２Ｙｅを、Ｒ画素８およびＧ画素１０のそれぞれにおける実効電圧の差ΔＶ１２ＲおよびΔＶ１２Ｇに比べて小さくすることによって、例えば、以下のような効果を奏する。 As described above, by making the effective voltage difference ΔV12Ye in the Ye pixel 14 smaller than the effective voltage differences ΔV12R and ΔV12G in the R pixel 8 and the G pixel 10, for example, the following effects can be obtained.
　すなわち、Ｒ画素８、Ｇ画素１０、および、Ｙｅ画素１４の表示する画像の輝度に対して、低階調においては、Ｒ画素８の備える明画素８ａ、Ｇ画素１０の備える明画素１０ａ、および、Ｙｅ画素１４の備える明画素１４ａが主に寄与し、階調が上がるにつれて、Ｙｅ画素１４の備える暗画素１４ｂが寄与し始め、さらに階調が上がるにつれて、Ｒ画素８の備える暗画素８ｂ、および、Ｇ画素１０の備える暗画素１０ｂが寄与し始める。 That is, with respect to the luminance of the image displayed by the R pixel 8, the G pixel 10, and the Ye pixel 14, in a low gradation, the bright pixel 8a included in the R pixel 8, the bright pixel 10a included in the G pixel 10, and , The bright pixel 14a included in the Ye pixel 14 mainly contributes, and as the gradation increases, the dark pixel 14b included in the Ye pixel 14 starts to contribute, and as the gradation further increases, the dark pixel 8b included in the R pixel 8. The dark pixel 10b included in the G pixel 10 starts to contribute.
　換言すれば、本実施形態に係る液晶表示装置１においては、赤色、緑色、および、黄色を成分として含む色の輝度が、階調が上がるに従い、少なくとも３段階に分かれて立ち上がる。 In other words, in the liquid crystal display device 1 according to the present embodiment, the luminance of the color including red, green, and yellow as components rises in at least three stages as the gradation increases.
　これは、本実施形態に係る液晶表示装置１が、赤色、緑色、および、黄色を成分として含む色を表示する場合、画素が副画素に少なくとも３分割されていることと同様の効果を奏することを示している。したがって、本実施形態に係る液晶表示装置１においては、特にＸ値およびＹ値についてのｌｏｃａｌγを、より一定に近づけることができる。 When the liquid crystal display device 1 according to the present embodiment displays colors including red, green, and yellow as components, the same effect as that in which the pixel is divided into at least three sub-pixels is obtained. Is shown. Therefore, in the liquid crystal display device 1 according to the present embodiment, the local γ particularly with respect to the X value and the Y value can be made more constant.
　一方で、ＤＲ＝ＤＧ＝ＤＹｅに設定されている比較例に係る液晶表示装置においては、Ｙｅ画素１４における実効電圧の差ΔＶ１２Ｙｅが、Ｒ画素８およびＧ画素１０のそれぞれにおける実効電圧の差ΔＶ１２ＲおよびΔＶ１２Ｇに等しい。 On the other hand, in the liquid crystal display device according to the comparative example in which DR = DG = DYe, the effective voltage difference ΔV12Ye in the Ye pixel 14 is equal to the effective voltage difference ΔV12R in the R pixel 8 and the G pixel 10, respectively. Equal to ΔV12G.
　このため、比較例に係る液晶表示装置における低階調においては、Ｒ画素８の備える明画素８ａ、Ｇ画素１０の備える明画素１０ａ、および、Ｙｅ画素１４の備える明画素１４ａが主に寄与し、階調が上がるにつれて、Ｙｅ画素１４の備える暗画素１４ｂ、Ｒ画素８の備える暗画素８ｂ、および、Ｇ画素１０の備える暗画素１０ｂが一様に寄与し始める。したがって、比較例に係る液晶表示装置においては、赤色、緑色、および、黄色を成分として含む色の輝度が、２段階に分かれて立ち上がるに過ぎない。 Therefore, in the low gradation in the liquid crystal display device according to the comparative example, the bright pixel 8a included in the R pixel 8, the bright pixel 10a included in the G pixel 10, and the bright pixel 14a included in the Ye pixel 14 mainly contribute. As the gradation level increases, the dark pixel 14b included in the Ye pixel 14, the dark pixel 8b included in the R pixel 8, and the dark pixel 10b included in the G pixel 10 start to contribute uniformly. Therefore, in the liquid crystal display device according to the comparative example, the luminance of the color including red, green, and yellow as components only rises in two stages.
　このように、本実施形態に係る液晶表示装置１は、容量比ＤＹｅを、容量比ＤＲおよび容量比ＤＧに比べて小さく設定することによって、赤色、緑色、および、黄色を成分として含む色の輝度を、階調が上がるに従い、少なくとも３段階に分かれて立ち上げることができるので、比較例に係る液晶表示装置に比べて、特にＸ値およびＹ値についてのｌｏｃａｌγを、より一定に近づけることができる。したがって、液晶表示装置１は、斜め視野角における色ずれの現象を効果的に抑制することができる。 As described above, the liquid crystal display device 1 according to the present embodiment sets the capacitance ratio DYe to be smaller than the capacitance ratio DR and the capacitance ratio DG, so that the luminance of the color including red, green, and yellow as components is set. Can be raised in at least three stages as the gray level increases, so that the local γ particularly for the X value and the Y value can be made closer to constant as compared with the liquid crystal display device according to the comparative example. . Therefore, the liquid crystal display device 1 can effectively suppress the phenomenon of color misregistration at an oblique viewing angle.
　以下では、図６～図９を参照して、本実施形態に係る液晶表示装置１の奏する効果について、より具体的に説明する。 Hereinafter, the effects produced by the liquid crystal display device 1 according to the present embodiment will be described more specifically with reference to FIGS.
　図６は、本実施形態に係る液晶表示装置１の、正面視角における、階調と三刺激値（Ｘ値、Ｙ値、Ｚ値）との関係（特性）を示す図である。 FIG. 6 is a diagram showing a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device 1 according to the present embodiment.
　図６に示すように、正面視角においては、階調とＸ値、Ｙ値、Ｚ値との関係を示すグラフは、いずれも一定のγ（ガンマ）値を有する曲線となっている。したがって、本実施形態に係る液晶表示装置１の表示画面を正面から観察した場合は、色ずれの現象は発生しない。 As shown in FIG. 6, at the front viewing angle, the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant γ (gamma) value. Therefore, when the display screen of the liquid crystal display device 1 according to the present embodiment is observed from the front, the phenomenon of color misregistration does not occur.
　図７は、本実施形態に係る液晶表示装置１の、斜め視角（より具体的には極角６０度）における階調－ＸＹＺ値特性を示す図である。 FIG. 7 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device 1 according to the present embodiment.
　図７に示すように、Ｘ値およびＹ値の双方について、略１００階調～略１５０階調の範囲におけるγ値の変化が、比較例に係る液晶表示装置に比べて小さくなっている。このように、本実施形態に係る液晶表示装置１においては、Ｘ値およびＹ値を示すグラフの曲線が、γ値が一定である理想曲線により近いものとなるため、色ずれの現象が抑制される。 As shown in FIG. 7, for both the X value and the Y value, the change in the γ value in the range of approximately 100 gradations to approximately 150 gradations is smaller than that of the liquid crystal display device according to the comparative example. As described above, in the liquid crystal display device 1 according to the present embodiment, the curve of the graph showing the X value and the Y value is closer to the ideal curve having a constant γ value, so that the phenomenon of color shift is suppressed. The
　図８は、本実施形態に係る液晶表示装置１の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。 FIG. 8 is a diagram showing the gradation-local γ characteristic at the polar angle of 60 degrees of the liquid crystal display device 1 according to the present embodiment.
　図８から明らかなように、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、略２０階調から略２２０階調までの範囲において、略一定の値をとっている。これは、比較例に係る液晶表示装置におけるＸ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値が、略１００階調～略１５０階調の範囲において、大きく変化していることと対照的である。 As is clear from FIG. 8, the value of local γ related to the X value and the value of local γ related to the Y value take substantially constant values in a range from about 20 gradations to about 220 gradations. This is in contrast to the fact that the value of local γ relating to the X value and the value of local γ relating to the Y value in the liquid crystal display device according to the comparative example change greatly in the range of approximately 100 gradations to approximately 150 gradations. It is.
　なお、Ｙ値のｌｏｃａｌγの中間調（３２階調から１９２階調）における標準偏差σは、σ＝０．２５８であり、比較例に係る液晶表示装置における標準偏差σ＝０．３８７に比べて小さい。このことからも、斜め視野角におけるＸ値およびＹ値の特性が、正面視野角における特性により近いことが分かる。 Note that the standard deviation σ in the halftone (32 gradations to 192 gradations) of the local γ of the Y value is σ = 0.258, compared with the standard deviation σ = 0.387 in the liquid crystal display device according to the comparative example. small. This also shows that the characteristics of the X value and the Y value at the oblique viewing angle are closer to the characteristics at the front viewing angle.
　以上のように、本実施形態に係る液晶表示装置１によれば、Ｙｅ画素１４における実効電圧の差ΔＶ１２Ｙｅを、Ｒ画素８およびＧ画素１０のそれぞれにおける実効電圧の差ΔＶ１２ＲおよびΔＶ１２Ｇに比べて小さくすることによって、斜め視野角における色ずれの現象を効果的に抑制することができる。 As described above, according to the liquid crystal display device 1 according to the present embodiment, the effective voltage difference ΔV12Ye in the Ye pixel 14 is smaller than the effective voltage differences ΔV12R and ΔV12G in the R pixel 8 and the G pixel 10, respectively. By doing so, the phenomenon of color misregistration at an oblique viewing angle can be effectively suppressed.
　図９（ａ）は、本実施形態に係る液晶表示装置１において、各副画素における液晶容量が互いに等しく設定されている場合に、試験的に設定された補助容量ＣｓＹｅの補助容量ＣｓＧに対する比（ＣｓＹｅ／ＣｓＧ）と、各比に対応するＹ値のｌｏｃａｌγの中間調（３２階調から１９２階調）における標準偏差σとの関係を示す表である。また、図９（ｂ）は、上記比ＣｓＹｅ／ＣｓＧと、上記標準偏差σとの関係を示すグラフである。 FIG. 9A shows the ratio of the auxiliary capacitance CsYe to the auxiliary capacitance CsG set experimentally when the liquid crystal capacitances in the sub-pixels are set to be equal to each other in the liquid crystal display device 1 according to the present embodiment. It is a table | surface which shows the relationship between CsYe / CsG) and the standard deviation (sigma) in the halftone (32 gradations to 192 gradations) of local (gamma) of Y value corresponding to each ratio. FIG. 9B is a graph showing the relationship between the ratio CsYe / CsG and the standard deviation σ.
　図９（ａ）～（ｂ）から明らかなように、上記標準偏差σは、ＣｓＹｅ／ＣｓＧ＝１／３の付近において最小値をとっている。したがって、各副画素における液晶容量が互いに等しく設定されている場合には、ＣｓＹｅ／ＣｓＧ＝１／３となるように、各補助容量を設定することによって、色ずれの現象を最も効果的に抑制することができる。 As is clear from FIGS. 9A to 9B, the standard deviation σ has a minimum value in the vicinity of CsYe / CsG = 1/3. Therefore, when the liquid crystal capacitances in the sub-pixels are set to be equal to each other, the color shift phenomenon is most effectively suppressed by setting each auxiliary capacitance so that CsYe / CsG = 1/3. can do.
　上述したように、本実施形態に係る液晶表示装置１においては、ＤＲ＝ＤＧ＝０．６、および、ＤＹｅ＝０．２を満たすように、各補助容量が設定されているが、これは、各副画素における液晶容量が互いに等しく設定されている場合に、ＣｓＹｅ／ＣｓＧ＝１／３を満たすように各補助容量が設定されていることに対応している。 As described above, in the liquid crystal display device 1 according to the present embodiment, each auxiliary capacitor is set so as to satisfy DR = DG = 0.6 and DYe = 0.2. This corresponds to the case where each auxiliary capacitor is set so as to satisfy CsYe / CsG = 1/3 when the liquid crystal capacitors in each sub-pixel are set to be equal to each other.
　したがって、本実施形態に係る液晶表示装置１は、各補助容量が、色ずれの現象を最も効果的に抑制することができるように、最適化された液晶表示装置であると表現することができる。 Therefore, the liquid crystal display device 1 according to the present embodiment can be expressed as an optimized liquid crystal display device so that each auxiliary capacitor can most effectively suppress the phenomenon of color misregistration. .
　また、図９（ａ）～（ｂ）から明らかなように、０．１＜ＣｓＹｅ／ＣｓＧ＜１の区間において、上記標準偏差σが、ＣｓＹｅ／ＣｓＧ＝１である場合の標準偏差σよりも小さくなっている。これは、各副画素における液晶容量が互いに等しく設定されている場合には、０．１＜ＣｓＹｅ／ＣｓＧ＜１を満たすように、各補助容量を設定することによって、ＣｓＹｅ／ＣｓＧ＝１とした場合に比べて、色ずれの現象を、より効果的に抑制することができることを示している。 Further, as is clear from FIGS. 9A to 9B, the standard deviation σ is greater than the standard deviation σ when CsYe / CsG = 1 in the interval of 0.1 <CsYe / CsG <1. It is getting smaller. This is because CsYe / CsG = 1 is set by setting each auxiliary capacity so as to satisfy 0.1 <CsYe / CsG <1 when the liquid crystal capacity in each sub-pixel is set equal to each other. It shows that the phenomenon of color misregistration can be suppressed more effectively than in the case.
　したがって、本実施形態に係る液晶表示装置１においては、ＣｓＹｅ／ＣｓＧ＝１／３に限らず、０．１＜ＣｓＹｅ／ＣｓＧ＜１を満たすように各補助容量を設定してもよく、そのような場合についても、本実施形態に係る液晶表示装置１は、色ずれの現象を効果的に抑制することができる。 Therefore, in the liquid crystal display device 1 according to the present embodiment, each auxiliary capacitor may be set so as to satisfy 0.1 <CsYe / CsG <1, without being limited to CsYe / CsG = 1/3. Even in such a case, the liquid crystal display device 1 according to the present embodiment can effectively suppress the phenomenon of color misregistration.
　〔実施形態２〕
　実施形態１においては、本発明をマルチ画素駆動（Multi Pixel Drive）方式を用いて実現する場合について説明を行ったが、本発明は、そのような駆動方式に限定されるものではない。以下では、実施形態２として、本発明を３ＴＦＴ駆動方式を用いて実現する場合について図１０～図１８を参照して説明を行う。 [Embodiment 2]
In the first embodiment, the case where the present invention is realized by using a multi-pixel drive method has been described. However, the present invention is not limited to such a drive method. In the following, as a second embodiment, a case where the present invention is realized using a 3TFT driving method will be described with reference to FIGS.
　以下の説明では、本発明の効果が顕著に現れる、誘電異方性が負の液晶材料を用いた垂直配向型液晶表示装置（ＶＡモードの液晶表示装置）を例示するが、本発明はこれに限定されず、例えばＴＮモードの液晶表示装置にも適用できる。 In the following description, a vertical alignment type liquid crystal display device (VA mode liquid crystal display device) using a liquid crystal material having a negative dielectric anisotropy, in which the effect of the present invention appears remarkably, will be described. For example, the present invention can be applied to a TN mode liquid crystal display device.
　（液晶表示装置１００の構成）
　図１０は、本実施形態に係る液晶表示装置であって、３ＴＦＴ駆動方式により駆動する液晶表示装置１００における、画素の等価回路を示す図である。図１０に示すように、液晶表示装置１００は、複数のゲートバスライン２’、複数のソースバスライン４’、複数のＣＳバスライン６’（補助容量配線または蓄積容量バスラインと称することもある）、複数のスイッチング素子ＴＦＴ１’、複数のスイッチング素子ＴＦＴ２’、複数のスイッチング素子ＴＦＴ３’、複数の補助容量Ｃｓ１’、複数の補助容量Ｃｓ２’、複数の液晶容量Ｃｌｃ１’、複数の液晶容量Ｃｌｃ２’、および複数のキャパシタ（蓄積容量）Ｃｄ’を備えている。液晶表示装置１００には複数の画素が形成されており、各画素を３ＴＦＴ駆動方式によって駆動する。各画素はいずれも液晶層と、当該液晶層に電圧を印加する電極とを有し、行および列を有するマトリックス状に配列されている。 (Configuration of the liquid crystal display device 100)
FIG. 10 is a diagram showing an equivalent circuit of a pixel in the liquid crystal display device 100 according to the present embodiment, which is driven by the 3 TFT driving method. As shown in FIG. 10, the liquid crystal display device 100 may be referred to as a plurality of gate bus lines 2 ′, a plurality of source bus lines 4 ′, and a plurality of CS bus lines 6 ′ (auxiliary capacitor lines or storage capacitor bus lines). ), A plurality of switching elements TFT1 ′, a plurality of switching elements TFT2 ′, a plurality of switching elements TFT3 ′, a plurality of auxiliary capacitors Cs1 ′, a plurality of auxiliary capacitors Cs2 ′, a plurality of liquid crystal capacitors Clc1 ′, and a plurality of liquid crystal capacitors Clc2 ′. , And a plurality of capacitors (storage capacitors) Cd ′. A plurality of pixels are formed in the liquid crystal display device 100, and each pixel is driven by a 3TFT driving method. Each pixel has a liquid crystal layer and an electrode for applying a voltage to the liquid crystal layer, and is arranged in a matrix having rows and columns.
　図１０において、ゲートバスライン２ｌ’は、ｌ（ただしｌは正の整数）本目のゲートバスライン２’を示す。また、ソースバスライン４ｍ’は、ｍ（ただしｍは正の整数）本目のソースバスライン４’を示す。また、ＣＳバスライン６ｎ’は、ｎ（ただしｎは正の整数）本目のＣＳバスライン６’を示す。 In FIG. 10, a gate bus line 2l 'indicates l (where l is a positive integer) first gate bus line 2'. The source bus line 4m ′ indicates the m-th source bus line 4 ′ (where m is a positive integer). The CS bus line 6n 'indicates the nth (where n is a positive integer) CS bus line 6'.
　（ドライバ）
　特に図示はしないが、液晶表示装置１００には、各ゲートバスライン２’に走査信号を供給するゲートドライバと、各ソースバスライン４’にデータ信号を供給するソースドライバと、各ＣＳバスライン６’に補助容量駆動信号を供給するＣＳドライバとが、それぞれ接続されている。これらのドライバはいずれも、図示しない制御回路から出力された制御信号に基づいて動作する。 (driver)
Although not particularly illustrated, the liquid crystal display device 100 includes a gate driver that supplies a scanning signal to each gate bus line 2 ′, a source driver that supplies a data signal to each source bus line 4 ′, and each CS bus line 6. A CS driver for supplying a storage capacitor drive signal to each other is connected. Each of these drivers operates based on a control signal output from a control circuit (not shown).
　（画素構造）
　複数のゲートバスライン２’および複数のソースバスライン４’は、図示しない絶縁膜を介して、互いに交差して形成されている。液晶表示装置１００では、１つのゲートバスライン２’と１つのソースバスライン４’とによって画定される領域ごとに、１つの画素が形成される。当該画素は、複数の互いに異なる種類の色のうちいずれかを個別に表示する。本実施形態においては、上記複数の互いに異なる種類の色には、複数の原色、および、該複数の原色のうち少なくとも２つの原色を組み合わせることによって得られる少なくとも１つ以上の色が含まれる。以下では、特に、上記複数の互いに異なる種類の色が、光の３原色（以下、単に「３原色」と呼ぶ）として、赤色、緑色、および青色を含み、上記複数の原色のうち少なくとも２つの原色を組み合わせることによって得られる色として、黄色（赤色および緑色の組み合わせ）を含む場合について説明する。 (Pixel structure)
The plurality of gate bus lines 2 ′ and the plurality of source bus lines 4 ′ are formed so as to intersect with each other via an insulating film (not shown). In the liquid crystal display device 100, one pixel is formed for each region defined by one gate bus line 2 ′ and one source bus line 4 ′. The pixel individually displays one of a plurality of different types of colors. In the present embodiment, the plurality of different types of colors include a plurality of primary colors and at least one or more colors obtained by combining at least two primary colors among the plurality of primary colors. In the following, in particular, the plurality of different types of colors include red, green, and blue as the three primary colors of light (hereinafter simply referred to as “three primary colors”), and at least two of the plurality of primary colors A case where yellow (a combination of red and green) is included as a color obtained by combining primary colors will be described.
　液晶表示装置１００内には、赤色を表示するＲ画素８’、緑色を表示するＧ画素１０’、青色を表示するＢ画素１２’、および、黄色を表示するＹｅ画素１４’がそれぞれ形成されている。これらの画素を組み合わせて用いることによって、所望のカラー画像を表示する。 In the liquid crystal display device 100, an R pixel 8 ′ for displaying red, a G pixel 10 ′ for displaying green, a B pixel 12 ′ for displaying blue, and a Ye pixel 14 ′ for displaying yellow are formed. Yes. By using these pixels in combination, a desired color image is displayed.
　このように、液晶表示装置１００が、赤色、緑色、および青色の３原色をそれぞれ表示する画素のみならず、３原色以外の色である黄色を表示する画素を備えることによって、実施形態１に係る液晶表示装置１と同様に、３原色を表示する画素のみを備える構成に比べて、それぞれの画素によって表示される色の混色により表現できる色の数を格段に増加させることができる。また、ライトブルー、イエロー、および、ゴールド等の色の主観的な美しさを格段に向上させることができる。 As described above, the liquid crystal display device 100 includes not only pixels that display the three primary colors of red, green, and blue, but also pixels that display yellow, which is a color other than the three primary colors, according to the first embodiment. Similar to the liquid crystal display device 1, the number of colors that can be expressed by the color mixture of colors displayed by the respective pixels can be remarkably increased as compared with the configuration including only the pixels that display the three primary colors. In addition, the subjective beauty of colors such as light blue, yellow, and gold can be significantly improved.
　（明画素および暗画素）
　Ｒ画素８’、Ｇ画素１０’、Ｂ画素１２’、および、Ｙｅ画素１４’は、いずれも、それぞれ液晶層に互いに異なる電圧を印加することができる２つ副画素（明画素および暗画素）を有している。Ｒ画素８’は明画素８ａ’および暗画素８ｂ’を有し、Ｇ画素１０’は明画素１０ａ’および暗画素１０ｂ’を有し、Ｂ画素１２’は明画素１２ａ’および暗画素１２ｂ’を有し、Ｙｅ画素１４’は明画素１４ａ’および暗画素１４ｂ’を有している。 (Bright and dark pixels)
Each of the R pixel 8 ', the G pixel 10', the B pixel 12 ', and the Ye pixel 14' has two sub-pixels (bright pixel and dark pixel) that can apply different voltages to the liquid crystal layer. have. The R pixel 8 ′ has a bright pixel 8a ′ and a dark pixel 8b ′, the G pixel 10 ′ has a bright pixel 10a ′ and a dark pixel 10b ′, and the B pixel 12 ′ has a bright pixel 12a ′ and a dark pixel 12b ′. The Ye pixel 14 'has a bright pixel 14a' and a dark pixel 14b '.
　各副画素は、いずれも、対向電極と、液晶層を介して当該対向電極に対向する副画素電極とによって形成される液晶容量を有している。さらに、副画素電極に電気的に接続された補助容量電極と、絶縁層と、当該絶縁層を介して補助容量電極と対向する補助容量対向電極とによって形成された補助容量も有している。また、各暗画素は、何れも、一端がＣＳバスライン６’に接続された蓄積容量も有している。 Each sub-pixel has a liquid crystal capacitance formed by a counter electrode and a sub-pixel electrode facing the counter electrode via a liquid crystal layer. Further, it also has an auxiliary capacitance formed by an auxiliary capacitance electrode electrically connected to the subpixel electrode, an insulating layer, and an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode through the insulating layer. Each dark pixel also has a storage capacitor with one end connected to the CS bus line 6 '.
　（液晶容量および補助容量）
　各画素の有する副画素は、液晶容量を有している。明画素は、液晶容量Ｃｌｃ１’を有しており、暗画素は液晶容量Ｃｌｃ２’を有している。 (Liquid crystal capacity and auxiliary capacity)
A sub-pixel included in each pixel has a liquid crystal capacitance. The bright pixel has a liquid crystal capacitance Clc1 ′, and the dark pixel has a liquid crystal capacitance Clc2 ′.
　より具体的には、図１０に示すように、Ｒ画素８’の明画素８ａ’は、液晶容量Ｃｌｃ１Ｒ’を有しており、暗画素８ｂ’は、液晶容量Ｃｌｃ２Ｒ’を有している。同様に、Ｇ画素１０’の明画素１０ａ’は、液晶容量Ｃｌｃ１Ｇ’を有しており、暗画素１０ｂ’は、液晶容量Ｃｌｃ２Ｇ’を有しており、Ｂ画素１２’の明画素１２ａ’は、液晶容量Ｃｌｃ１Ｂ’を有しており、暗画素１２ｂ’は、液晶容量Ｃｌｃ２Ｂ’を有しており、Ｙｅ画素１４’の明画素１４ａ’は、液晶容量Ｃｌｃ１Ｙｅ’を有しており、暗画素１４ｂ’は、液晶容量Ｃｌｃ２Ｙｅ’を有している。 More specifically, as shown in FIG. 10, the bright pixel 8a 'of the R pixel 8' has a liquid crystal capacitance Clc1R ', and the dark pixel 8b' has a liquid crystal capacitance Clc2R '. Similarly, the bright pixel 10a ′ of the G pixel 10 ′ has a liquid crystal capacitor Clc1G ′, the dark pixel 10b ′ has a liquid crystal capacitor Clc2G ′, and the bright pixel 12a ′ of the B pixel 12 ′ is , The dark pixel 12b ′ has the liquid crystal capacitor Clc2B ′, the bright pixel 14a ′ of the Ye pixel 14 ′ has the liquid crystal capacitor Clc1Ye ′, and the dark pixel 14b ′ has a liquid crystal capacitance Clc2Ye ′.
　また、液晶容量Ｃｌｃ１’には、電気的に並列に第１の補助容量Ｃｓ１’が接続されており、液晶容量Ｃｌｃ２’には、電気的に並列に第２の補助容量Ｃｓ２’が接続されている。 The first auxiliary capacitor Cs1 ′ is electrically connected in parallel to the liquid crystal capacitor Clc1 ′, and the second auxiliary capacitor Cs2 ′ is electrically connected in parallel to the liquid crystal capacitor Clc2 ′. Yes.
　より具体的には、液晶容量Ｃｌｃ１Ｒ’には、電気的に並列に補助容量Ｃｓ１Ｒ’が接続され、液晶容量Ｃｌｃ２Ｒ’には、電気的に並列に補助容量Ｃｓ２Ｒ’が接続されている。同様に、液晶容量Ｃｌｃ１Ｇ’には、電気的に並列に補助容量Ｃｓ１Ｇ’が接続され、液晶容量Ｃｌｃ２Ｇ’には、電気的に並列に補助容量Ｃｓ２Ｇ’が接続されており、液晶容量Ｃｌｃ１Ｂ’には、電気的に並列に補助容量Ｃｓ１Ｂ’が接続され、液晶容量Ｃｌｃ２Ｂ’には、電気的に並列に補助容量Ｃｓ２Ｂ’が接続されており、液晶容量Ｃｌｃ１Ｙｅ’には、電気的に並列に補助容量Ｃｓ１Ｙｅ’が接続され、液晶容量Ｃｌｃ２Ｙｅ’には、電気的に並列に補助容量Ｃｓ２Ｙｅ’が接続されている。 More specifically, an auxiliary capacitor Cs1R 'is electrically connected in parallel to the liquid crystal capacitor Clc1R', and an auxiliary capacitor Cs2R 'is electrically connected in parallel to the liquid crystal capacitor Clc2R'. Similarly, an auxiliary capacitor Cs1G ′ is electrically connected in parallel to the liquid crystal capacitor Clc1G ′, and an auxiliary capacitor Cs2G ′ is electrically connected in parallel to the liquid crystal capacitor Clc2G ′, and is connected to the liquid crystal capacitor Clc1B ′. Is electrically connected in parallel to the auxiliary capacitor Cs1B ′, the liquid crystal capacitor Clc2B ′ is electrically connected in parallel to the auxiliary capacitor Cs2B ′, and the liquid crystal capacitor Clc1Ye ′ is electrically connected in parallel. A capacitor Cs1Ye ′ is connected, and an auxiliary capacitor Cs2Ye ′ is electrically connected in parallel to the liquid crystal capacitor Clc2Ye ′.
　（蓄積容量）
　各暗画素は、蓄積容量Ｃｄ’を有している。より具体的には、図１０に示すように、Ｒ画素８’の暗画素８ｂ’は、蓄積容量ＣｄＲ’を有しており、Ｇ画素１０’の暗画素１０ｂ’は、蓄積容量ＣｄＧ’を有しており、Ｂ画素１２’の暗画素１２ｂ’は、蓄積容量ＣｄＢ’を有しており、Ｙｅ画素１４’の暗画素１４ｂ’は、蓄積容量ＣｄＹｅ’を有している。 (Storage capacity)
Each dark pixel has a storage capacitor Cd ′. More specifically, as shown in FIG. 10, the dark pixel 8b ′ of the R pixel 8 ′ has a storage capacitor CdR ′, and the dark pixel 10b ′ of the G pixel 10 ′ has a storage capacitor CdG ′. The dark pixel 12b ′ of the B pixel 12 ′ has a storage capacitor CdB ′, and the dark pixel 14b ′ of the Ye pixel 14 ′ has a storage capacitor CdYe ′.
　各蓄積容量Ｃｄ’は、対応するＴＦＴ３’のソース電極に接続された蓄積容量電極と、絶縁膜と、当該絶縁膜を介して蓄積容量電極に対向する蓄積容量対向電極とによって形成されている。また、各蓄積容量対向電極は、ＣＳバスライン６ｎ’に接続されている。 Each storage capacitor Cd 'is formed by a storage capacitor electrode connected to the source electrode of the corresponding TFT 3', an insulating film, and a storage capacitor counter electrode facing the storage capacitor electrode through the insulating film. Each storage capacitor counter electrode is connected to a CS bus line 6n '.
　（スイッチング素子ＴＦＴ１’およびＴＦＴ２’）
　Ｒ画素８’、Ｇ画素１０’、Ｂ画素１２’、およびＹｅ画素１４’には、いずれも、ＴＦＴ（薄膜トランジスタ）１’、およびＴＦＴ２’がそれぞれ形成されている。各補助容量Ｃｓ’の補助容量電極は、それぞれ対応するＴＦＴ１’またはＴＦＴ２’のドレイン電極に接続されている。ＴＦＴ１’およびＴＦＴ２’のゲート電極は共通のゲートバスライン２ｌ’に接続されており、ＴＦＴ１’およびＴＦＴ２’のソース電極は共通のソースバスライン４’に接続されている。すなわち、図１０に示すように、Ｒ画素８’のＴＦＴ１Ｒ’およびＴＦＴ２Ｒ’のソース電極は、ソースバスライン４ｍ’に接続されている。同様に、Ｇ画素１０のＴＦＴ１Ｇ’およびＴＦＴ２Ｇ’のソース電極は、ソースバスライン４（ｍ＋１）’に接続されており、Ｂ画素１２’のＴＦＴ１Ｂ’およびＴＦＴ２Ｂ’のソース電極は、ソースバスライン４（ｍ＋２）’に接続されており、Ｙｅ画素１４’のＴＦＴ１Ｙｅ’およびＴＦＴ２Ｙｅ’のソース電極は、ソースバスライン４（ｍ＋３）’に接続されている。 (Switching elements TFT1 ′ and TFT2 ′)
In each of the R pixel 8 ′, the G pixel 10 ′, the B pixel 12 ′, and the Ye pixel 14 ′, a TFT (thin film transistor) 1 ′ and a TFT 2 ′ are formed. The auxiliary capacitance electrode of each auxiliary capacitance Cs ′ is connected to the drain electrode of the corresponding TFT 1 ′ or TFT 2 ′. The gate electrodes of TFT1 'and TFT2' are connected to a common gate bus line 21 ', and the source electrodes of TFT1' and TFT2 'are connected to a common source bus line 4'. That is, as shown in FIG. 10, the source electrodes of the TFT 1R ′ and TFT 2R ′ of the R pixel 8 ′ are connected to the source bus line 4m ′. Similarly, the source electrodes of TFT 1G ′ and TFT 2G ′ of the G pixel 10 are connected to the source bus line 4 (m + 1) ′, and the source electrodes of TFT 1B ′ and TFT 2B ′ of the B pixel 12 ′ are connected to the source bus line 4 The source electrodes of the TFT 1Ye ′ and the TFT 2Ye ′ of the Ye pixel 14 ′ are connected to the source bus line 4 (m + 3) ′.
　ＴＦＴ１’、ＴＦＴ２’、および後述するＴＦＴ３’は、それぞれ、自身の備えるゲート電極にハイレベルのゲート信号が印加されているとき、導通状態（オン状態）となり、自身の備えるゲート電極にローレベルのゲート信号が印加されているとき、非導通状態（オフ状態、遮断状態）となる。 Each of the TFT 1 ′, TFT 2 ′, and TFT 3 ′ described later is in a conductive state (on state) when a high level gate signal is applied to its own gate electrode, and the low level is applied to its own gate electrode. When the gate signal is applied, the non-conduction state (off state, cutoff state) is established.
　（スイッチング素子ＴＦＴ３’）
　また、Ｒ画素８’、Ｇ画素１０’、Ｂ画素１２’、およびＹｅ画素１４’には、いずれも、対応するＴＦＴ３’がそれぞれ形成されている。ＴＦＴ３’のゲート電極は、当該画素の次段のゲートバスライン、すなわちゲートバスライン２（ｌ＋１）’に電気的に接続されている。各ＴＦＴ３’のドレイン電極は、コンタクトホールを介して各暗画素８ｂ’、１０ｂ’、１２ｂ’、および１４ｂ’の画素電極に電気的に接続されている。また、各ＴＦＴ３’のソース電極は、対応する蓄積容量Ｃｄ’の蓄積容量電極に接続されている。 (Switching element TFT3 ')
The R pixel 8 ′, the G pixel 10 ′, the B pixel 12 ′, and the Ye pixel 14 ′ are each formed with a corresponding TFT 3 ′. The gate electrode of the TFT 3 ′ is electrically connected to the next gate bus line of the pixel, that is, the gate bus line 2 (l + 1) ′. The drain electrode of each TFT 3 ′ is electrically connected to the pixel electrodes of the dark pixels 8b ′, 10b ′, 12b ′, and 14b ′ via contact holes. The source electrode of each TFT 3 ′ is connected to the storage capacitor electrode of the corresponding storage capacitor Cd ′.
　３ＴＦＴ駆動方式の液晶表示装置１００においては、ゲートバスライン２ｌ’が選択されて各明画素８ａ’、１０ａ’、１２ａ’、および１４ａ’の液晶容量Ｃｌｃ１’に電荷が蓄えられた後に、時間差で次のゲートバスライン２（ｌ＋１）’が選択されＴＦＴ３’がオン状態となることによって、電荷の再配分が生じ、各明画素の液晶容量Ｃｌｃ１’と各暗画素の液晶容量Ｃｌｃ２’との間に電圧差を生じさせている。これにより、各画素内に明画素８ａ’、１０ａ’、１２ａ’、１４ａ’、および、暗画素８ｂ’、１０ｂ’、１２ｂ’、１４ｂ’を形成させている。 In the 3 TFT drive type liquid crystal display device 100, after the gate bus line 2l ′ is selected and charges are stored in the liquid crystal capacitances Clc1 ′ of the respective bright pixels 8a ′, 10a ′, 12a ′, and 14a ′, the time difference occurs. When the next gate bus line 2 (l + 1) ′ is selected and the TFT 3 ′ is turned on, charge redistribution occurs, and the liquid crystal capacitance Clc1 ′ of each bright pixel and the liquid crystal capacitance Clc2 ′ of each dark pixel are between. This causes a voltage difference. Thus, bright pixels 8a ', 10a', 12a ', 14a' and dark pixels 8b ', 10b', 12b ', 14b' are formed in each pixel.
　（ＣＳバスライン６’）
　ゲートバスライン２’およびソースバスライン４’により画定された画素領域を横切るように、ＣＳバスライン６’がゲートバスライン２’に並列して延びている。各ＣＳバスライン６’は、液晶表示装置１００における同一行に形成されたＲ画素８’、Ｇ画素１０’、Ｂ画素１２’、および、Ｙｅ画素１４’に共通して設けられている。ＣＳバスライン６ｎ’は、補助容量Ｃｓ１Ｒ’、補助容量Ｃｓ２Ｒ’、補助容量Ｃｓ１Ｇ’、補助容量Ｃｓ２Ｇ’、補助容量Ｃｓ１Ｂ’、補助容量Ｃｓ２Ｂ、’補助容量Ｃｓ１Ｙｅ’補助容量Ｃｓ２Ｙｅ’、および、各蓄積容量対向電極に接続されている。 (CS bus line 6 ')
A CS bus line 6 ′ extends in parallel with the gate bus line 2 ′ so as to cross a pixel region defined by the gate bus line 2 ′ and the source bus line 4 ′. Each CS bus line 6 ′ is provided in common to the R pixel 8 ′, G pixel 10 ′, B pixel 12 ′, and Ye pixel 14 ′ formed in the same row in the liquid crystal display device 100. The CS bus line 6n ′ includes an auxiliary capacitor Cs1R ′, an auxiliary capacitor Cs2R ′, an auxiliary capacitor Cs1G ′, an auxiliary capacitor Cs2G ′, an auxiliary capacitor Cs1B ′, an auxiliary capacitor Cs2B, an “auxiliary capacitor Cs1Ye” and an auxiliary capacitor Cs2Ye. It is connected to the capacitor counter electrode.
　（液晶表示装置１００の動作）
　以下では、液晶表示装置１００における等価回路の駆動方法について図１１（ａ）～図１１（ｅ）を参照して説明する。なお、以下では、最初に、Ｒ画素８’の駆動について説明を行い、その後、Ｇ画素１０’、Ｂ画素１２’、およびＹｅ画素１４’の駆動について説明を行う。 (Operation of the liquid crystal display device 100)
Hereinafter, a method for driving an equivalent circuit in the liquid crystal display device 100 will be described with reference to FIGS. 11 (a) to 11 (e). In the following, driving of the R pixel 8 ′ will be described first, and thereafter driving of the G pixel 10 ′, the B pixel 12 ′, and the Ye pixel 14 ′ will be described.
　また、一般には、各補助容量の値、および、各液晶容量の値は、それぞれに印加される電圧への依存性を有するが、本実施形態においては本質的な事項ではないため、以下の説明ではそのような依存性を無視する。ただし、この前提は、本実施形態を限定するものではなく、そのような依存性がある場合に対しても、同様に適用することができる。 In general, the value of each auxiliary capacitance and the value of each liquid crystal capacitance have a dependency on the voltage applied to each, but are not essential matters in the present embodiment. So ignore such dependencies. However, this premise does not limit the present embodiment, and can be similarly applied to a case where there is such dependency.
　また、以下では、簡単のため、ＣＳバスライン６’の電位が０である場合を例にとり説明を行うが、本実施形態はこれに限定されるものではなく、実施形態１におけるＣＳバスライン６のように、ＣＳバスライン６’に矩形波の電圧信号が供給される構成としてもよい。 In the following, for the sake of simplicity, the case where the potential of the CS bus line 6 ′ is 0 will be described as an example. However, the present embodiment is not limited to this, and the CS bus line 6 in Embodiment 1 is not limited thereto. As described above, a rectangular wave voltage signal may be supplied to the CS bus line 6 ′.
　図１１は、液晶表示装置１００を駆動する際の各電圧の波形およびタイミングを模式的に示したタイミングチャートである。 FIG. 11 is a timing chart schematically showing the waveform and timing of each voltage when the liquid crystal display device 100 is driven.
　図１１（ａ）は、ソースドライバがソースバスライン４’に供給するデータ信号の電圧波形Ｖｓ’を示しており、図１１（ｂ）は、ゲートドライバがゲートバスライン２ｌ’に供給するゲート信号の電圧波形Ｖｇｌ’を示しており、図１１（ｃ）は、ゲートドライバがゲートバスライン２（ｌ＋１）’に供給するゲート信号の電圧波形Ｖｇ（ｌ＋１）’を示しており、図１１（ｄ）は、Ｒ画素８’の備える明画素８ａ’の副画素電極の電圧波形Ｖｌｃ１Ｒ’を示しており、図１１（ｅ）は、Ｒ画素８’の備える暗画素８ｂ’の副画素電極の電圧波形Ｖｌｃ２Ｒ’を示している。また、図中の破線は、対向電極の電圧波形ＣＯＭＭＯＮ（Ｖｃｏｍ）を示している。 FIG. 11A shows the voltage waveform Vs ′ of the data signal supplied from the source driver to the source bus line 4 ′, and FIG. 11B shows the gate signal supplied from the gate driver to the gate bus line 2l ′. FIG. 11C shows the voltage waveform Vg (l + 1) ′ of the gate signal supplied to the gate bus line 2 (l + 1) ′ by the gate driver, and FIG. ) Shows the voltage waveform Vlc1R ′ of the subpixel electrode of the bright pixel 8a ′ included in the R pixel 8 ′, and FIG. 11E shows the voltage of the subpixel electrode of the dark pixel 8b ′ included in the R pixel 8 ′. Waveform Vlc2R ′ is shown. Moreover, the broken line in the figure indicates the voltage waveform COMMON (Vcom) of the counter electrode.
　まず、時刻Ｔ１’において、ゲート信号の電圧Ｖｇｌ’が、ＶｇＬ（ロー）からＶｇＨ（ハイ）に変化することにより、ＴＦＴ１’とＴＦＴ２’とが同時に導通状態（オン状態）となる。これに伴い、明画素８ａ’の副画素電極、および、暗画素８ｂ’の副画素電極に対し、ソースバスライン４’を介してデータ信号の電圧が印加され、明画素８ａ’の副画素電極の電圧Ｖｌｃ１Ｒ’、および、暗画素８ｂ’の副画素電極の電圧Ｖｌｃ２Ｒ’は、データ信号の電圧Ｖｓ’へと変化し、
　Ｖｌｃ１Ｒ’＝Ｖｓ’　　　…（２０ａ）
　Ｖｌｃ２Ｒ’＝Ｖｓ’　　　…（２０ｂ）
となる。 First, at time T1 ′, the voltage Vgl ′ of the gate signal changes from VgL (low) to VgH (high), whereby the TFT1 ′ and the TFT2 ′ are simultaneously turned on (on state). Accordingly, the voltage of the data signal is applied to the subpixel electrode of the bright pixel 8a ′ and the subpixel electrode of the dark pixel 8b ′ via the source bus line 4 ′, and the subpixel electrode of the bright pixel 8a ′. Voltage Vlc1R ′ and the voltage Vlc2R ′ of the subpixel electrode of the dark pixel 8b ′ change to the voltage Vs ′ of the data signal,
Vlc1R ′ = Vs ′ (20a)
Vlc2R ′ = Vs ′ (20b)
It becomes.
　また、明画素８ａ’の補助容量Ｃｓ１Ｒ’、および、暗画素８ｂ’の補助容量Ｃｓ２Ｒ’に対しても、ソースバスライン４’を介してデータ信号の電圧が印加され、明画素８ａ’の補助容量電極、および、暗画素８ｂ’の補助容量電極の何れの電圧も、データ信号の電圧Ｖｓ’へと変化する。 Further, the voltage of the data signal is also applied to the auxiliary capacitor Cs1R ′ of the bright pixel 8a ′ and the auxiliary capacitor Cs2R ′ of the dark pixel 8b ′ via the source bus line 4 ′, thereby assisting the bright pixel 8a ′. Both the voltage of the capacitance electrode and the auxiliary capacitance electrode of the dark pixel 8b ′ change to the voltage Vs ′ of the data signal.
　ソースバスライン４を介して伝達されるデータ信号の電圧Ｖｓ’は当該画素において表示すべき階調に対応する表示電圧であり、ＴＦＴがオン状態の間（「選択期間」ということもある。）に、対応する画素に書き込まれる。 The voltage Vs ′ of the data signal transmitted through the source bus line 4 is a display voltage corresponding to the gradation to be displayed in the pixel, and the TFT is in an on state (sometimes referred to as “selection period”). Are written in the corresponding pixels.
　続いて、時刻Ｔ２’において、ゲート信号の電圧Ｖｇｌ’がＶｇＨからＶｇＬに変化することにより、ＴＦＴ１’とＴＦＴ２’とが同時に非導通状態（オフ状態）となる。これに伴い、明画素８ａ’の副画素電極、暗画素８ｂ’の副画素電極、明画素８ａ’の補助容量電極、および、暗画素８ｂ’の補助容量電極は、全てソースバスライン４’と電気的に絶縁される（この状態にある期間を「非選択期間」ということがある。）。 Subsequently, at time T2 ', the voltage Vgl' of the gate signal changes from VgH to VgL, so that the TFT 1 'and the TFT 2' are simultaneously turned off (off state). Accordingly, the sub-pixel electrode of the bright pixel 8a ′, the sub-pixel electrode of the dark pixel 8b ′, the auxiliary capacitance electrode of the bright pixel 8a ′, and the auxiliary capacitance electrode of the dark pixel 8b ′ are all connected to the source bus line 4 ′. It is electrically insulated (the period in this state may be referred to as “non-selection period”).
　また、ＴＦＴ１’およびＴＦＴ２’がオン状態からオフ状態に切り替わった直後、ＴＦＴ１’およびＴＦＴ２’の有する寄生容量等の影響による引き込み現象のために、それぞれの副画素電極の電圧Ｖｌｃ１Ｒ’およびＶｌｃ２Ｒ’は概ね同一の電圧ΔＶｄ’だけ低下するが、これは本質的な事項ではないため、以下の説明においては無視することにする。 Further, immediately after the TFT1 ′ and the TFT2 ′ are switched from the on state to the off state, the voltages Vlc1R ′ and Vlc2R ′ of the respective subpixel electrodes are caused by a pulling phenomenon due to the influence of the parasitic capacitance and the like of the TFT1 ′ and the TFT2 ′. Although it decreases by substantially the same voltage ΔVd ′, this is not an essential matter and will be ignored in the following description.
　続いて、時刻Ｔ３’において、ゲート信号の電圧Ｖｇ（ｌ＋１）’が、ＶｇＬからＶｇＨに変化することにより、ＴＦＴ３’が導通状態となる。これに伴い、暗画素８ｂ’の補助容量電極と蓄積容量電極とが導通状態となる。 Subsequently, at time T3 ', the voltage Vg (l + 1)' of the gate signal changes from VgL to VgH, so that the TFT 3 'becomes conductive. Accordingly, the storage capacitor electrode and the storage capacitor electrode of the dark pixel 8b 'are brought into conduction.
　これにより、暗画素８ｂ’の副画素電極の電圧Ｖｌｃ２Ｒ’は、
　Ｖｌｃ２Ｒ’＝Ｖｓ’－ΔＶＲ’　　　…（２１）
となる。ここで、ΔＶＲ’は、
ΔＶＲ’＝ＣｄＲ’／（Ｃｌｃ２Ｒ’＋Ｃｓ２Ｒ’＋ＣｄＲ’）　　　…（２２）
によって与えられる。 Thus, the voltage Vlc2R ′ of the subpixel electrode of the dark pixel 8b ′ is
Vlc2R ′ = Vs′−ΔVR ′ (21)
It becomes. Where ΔVR ′ is
ΔVR ′ = CdR ′ / (Clc2R ′ + Cs2R ′ + CdR ′) (22)
Given by.
　一方で、明画素８ａ’の副画素電極の電圧Ｖｌｃ１Ｒ’は、時刻Ｔ３’において、変化しない。 On the other hand, the voltage Vlc1R 'of the subpixel electrode of the bright pixel 8a' does not change at time T3 '.
　続いて、時刻Ｔ４’において、ゲート信号の電圧Ｖｇ（ｌ＋１）’がＶｇＨからＶｇＬに変化することにより、ＴＦＴ３’が非導通状態となる。これに伴い、暗画素８ｂ’の補助容量電極は、蓄積容量電極と絶縁される。ここで、ＴＦＴ３’の有する寄生容量等の影響による引き込み現象のために、副画素電極の電圧Ｖｌｃ２Ｒ’は概ね電圧ΔＶｄ’だけ低下するが、これは本質的な事項ではないため、ＴＦＴ１’およびＴＦＴ２’についての引き込み現象と同様に、以下の説明においては無視することにする。 Subsequently, at time T4 ', the voltage Vg (l + 1)' of the gate signal changes from VgH to VgL, so that the TFT 3 'is turned off. Accordingly, the storage capacitor electrode of the dark pixel 8b 'is insulated from the storage capacitor electrode. Here, because of the pull-in phenomenon due to the influence of the parasitic capacitance and the like of the TFT 3 ′, the voltage Vlc2R ′ of the sub-pixel electrode is decreased by approximately the voltage ΔVd ′. However, this is not an essential matter, so that the TFT 1 ′ and the TFT 2 Similar to the pull-in phenomenon for ', it will be ignored in the following description.
　以上の過程を経た後、Ｖｌｃ１Ｒ’およびＶｌｃ２Ｒ’の実効的な値は、
　Ｖｌｃ１Ｒ’＝Ｖｓ’　　　…（２３ａ）
　Ｖｌｃ２Ｒ’＝Ｖｓ’－ΔＶＲ’　　　…（２３ｂ）
となる。 After going through the above process, the effective values of Vlc1R ′ and Vlc2R ′ are
Vlc1R ′ = Vs ′ (23a)
Vlc2R ′ = Vs′−ΔVR ′ (23b)
It becomes.
　よって、明画素８ａおよび暗画素８ｂのそれぞれの液晶層に印加される実効電圧Ｖ１Ｒ’およびＶ２Ｒ’は、
　Ｖ１Ｒ’＝Ｖｌｃ１Ｒ’－Ｖｃｏｍ　　　…（２４ａ）
　Ｖ２Ｒ’＝Ｖｌｃ２Ｒ’－Ｖｃｏｍ　　　…（２４ｂ）
すなわち、
　Ｖ１Ｒ’＝Ｖｓ’－Ｖｃｏｍ　　　…（２５ａ）
　Ｖ２Ｒ’＝Ｖｓ’－ΔＶＲ’－Ｖｃｏｍ　　　…（２５ｂ）
となる。 Therefore, effective voltages V1R ′ and V2R ′ applied to the respective liquid crystal layers of the bright pixel 8a and the dark pixel 8b are:
V1R ′ = Vlc1R′−Vcom (24a)
V2R ′ = Vlc2R′−Vcom (24b)
That is,
V1R ′ = Vs′−Vcom (25a)
V2R ′ = Vs′−ΔVR′−Vcom (25b)
It becomes.
　したがって、Ｒ画素８’の備える明画素８ａ’および暗画素８ｂ’のぞれぞれの液晶層に印加される実効電圧の差（電位差）ΔＶ１２Ｒ’（＝Ｖ１Ｒ’－Ｖ２Ｒ’、Ｒ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｒ’＝ΔＶＲ’
　　　　　　　＝ＣｄＲ’／（Ｃｌｃ２Ｒ’＋Ｃｓ２Ｒ’＋ＣｄＲ’）　　　…（２６）
となる。 Accordingly, the effective voltage difference (potential difference) ΔV12R ′ (= V1R′−V2R ′) applied to the respective liquid crystal layers of the bright pixel 8a ′ and the dark pixel 8b ′ included in the R pixel 8 ′, ΔVα ”))
ΔV12R ′ = ΔVR ′
= CdR ′ / (Clc2R ′ + Cs2R ′ + CdR ′) (26)
It becomes.
　Ｇ画素１０’に関しても、同様の駆動が行われ、Ｇ画素１０’の備える明画素１０ａ’および暗画素１０ｂ’のぞれぞれの液晶層に印加される実効電圧の差ΔＶ１２Ｇ’（Ｇ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｇ’＝ＣｄＧ’／（Ｃｌｃ２Ｇ’＋Ｃｓ２Ｇ’＋ＣｄＧ’）　　　…（２７）
となる。 The G pixel 10 ′ is also driven in the same manner, and the difference ΔV12G ′ (G pixel) between the effective voltages applied to the respective liquid crystal layers of the bright pixel 10a ′ and the dark pixel 10b ′ included in the G pixel 10 ′. Is sometimes referred to as “ΔVα”).
ΔV12G ′ = CdG ′ / (Clc2G ′ + Cs2G ′ + CdG ′) (27)
It becomes.
　Ｂ画素１２’に関しても、同様の駆動が行われ、Ｂ画素１２’の備える明画素１２ａ’および暗画素１２ｂ’のぞれぞれの液晶層に印加される実効電圧の差ΔＶ１２Ｂ’（Ｂ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｂ’＝ＣｄＢ’／（Ｃｌｃ２Ｂ’＋Ｃｓ２Ｂ’＋ＣｄＢ’）　　　…（２８）
となる。 The same driving is performed for the B pixel 12 ′, and the difference ΔV12B ′ (B pixel) between the effective voltages applied to the liquid crystal layers of the bright pixel 12a ′ and the dark pixel 12b ′ included in the B pixel 12 ′. Is sometimes referred to as “ΔVα”).
ΔV12B ′ = CdB ′ / (Clc2B ′ + Cs2B ′ + CdB ′) (28)
It becomes.
　Ｙｅ画素１４’に関しても、同様の駆動が行われ、Ｙｅ画素１４’の備える明画素１４ａ’および暗画素１４ｂ’のぞれぞれの液晶層に印加される実効電圧の差ΔＶ１２Ｙｅ’（Ｙｅ画素に関する「ΔＶα」ということもある。）は、
　ΔＶ１２Ｙｅ’＝ＣｄＹｅ’／（Ｃｌｃ２Ｙｅ’＋Ｃｓ２Ｙｅ’＋ＣｄＹｅ’）　　　…（２９）
となる。 The same driving is performed on the Ye pixel 14 ′, and the difference ΔV12Ye ′ (Ye pixel) between the effective voltages applied to the respective liquid crystal layers of the bright pixel 14a ′ and the dark pixel 14b ′ included in the Ye pixel 14 ′. Is sometimes referred to as “ΔVα”).
ΔV12Ye ′ = CdYe ′ / (Clc2Ye ′ + Cs2Ye ′ + CdYe ′) (29)
It becomes.
　以下では、簡単のため、各暗画素における補助容量の値が０である場合、すなわち、Ｃｓ２Ｒ’＝Ｃｓ２Ｇ’＝Ｃｓ２Ｂ’＝Ｃｓ２Ｙｅ’＝０である場合について説明を行う。ただし、本実施形態は、これに限定されるものではなく、各暗画素における補助容量の値が０でない場合についても同様に適用することができる。 Hereinafter, for the sake of simplicity, the case where the value of the auxiliary capacitance in each dark pixel is 0, that is, the case where Cs2R ′ = Cs2G ′ = Cs2B ′ = Cs2Ye ′ = 0 will be described. However, the present embodiment is not limited to this, and can be similarly applied to the case where the value of the auxiliary capacitance in each dark pixel is not zero.
　各暗画素における補助容量の値が０である場合には、ΔＶ１２Ｒ’、ΔＶ１２Ｇ’、ΔＶ１２Ｂ’、およびΔＶ１２Ｙｅ’は、以下のように表される。 When the value of the auxiliary capacitance in each dark pixel is 0, ΔV12R ′, ΔV12G ′, ΔV12B ′, and ΔV12Ye ′ are expressed as follows.
　ΔＶ１２Ｒ’＝ＤＲ’／（１＋ＤＲ’）　　　…（２６’）
　ΔＶ１２Ｇ’＝ＤＧ’／（１＋ＤＧ’）　　　…（２７’）
　ΔＶ１２Ｂ’＝ＤＢ’／（１＋ＤＢ’）　　　…（２８’）
　ΔＶ１２Ｙｅ’＝ＤＹｅ’／（１＋ＤＹｅ’）　　　…（２９’）
ここで、ＤＲ’、ＤＧ’、ＤＧ’、およびＤＹｅ’は、各暗画素における液晶容量に対する蓄積容量の比（以下、単に「蓄積容量比」とも呼ぶ）を表しており、
　ＤＲ’＝ＣｄＲ’／Ｃｌｃ２Ｒ’　　　…（３０）
　ＤＢ’＝ＣｄＢ’／Ｃｌｃ２Ｂ’　　　…（３１）
　ＤＧ’＝ＣｄＧ’／Ｃｌｃ２Ｇ’　　　…（３２）
　ＤＹｅ’＝ＣｄＹｅ’／Ｃｌｃ２Ｙｅ’　　　…（３３）
によって与えられる。 ΔV12R ′ = DR ′ / (1 + DR ′) (26 ′)
ΔV12G ′ = DG ′ / (1 + DG ′) (27 ′)
ΔV12B ′ = DB ′ / (1 + DB ′) (28 ′)
ΔV12Ye ′ = DYe ′ / (1 + DYe ′) (29 ′)
Here, DR ′, DG ′, DG ′, and DYe ′ represent the ratio of the storage capacity to the liquid crystal capacity in each dark pixel (hereinafter also simply referred to as “storage capacity ratio”).
DR ′ = CdR ′ / Clc2R ′ (30)
DB ′ = CdB ′ / Clc2B ′ (31)
DG ′ = CdG ′ / Clc2G ′ (32)
DYe ′ = CdYe ′ / Clc2Ye ′ (33)
Given by.
　数式（２６’）～（２９’）および数式（３０）～（３３）から明らかなように、各暗画素における蓄積容量比の値を適宜変更することにより、各画素の備える副画素のそれぞれの液晶層に印加される実効電圧の差を所望の値に設定することができる。また、数式（２６）～（２９）から明らかなように、各暗画素における補助容量の値を適宜変更することによっても、各画素の備える副画素のそれぞれの液晶層に印加される実効電圧の差を所望の値に設定することができる。 As is clear from Equations (26 ′) to (29 ′) and Equations (30) to (33), by appropriately changing the value of the storage capacity ratio in each dark pixel, each of the sub-pixels included in each pixel is changed. The difference in effective voltage applied to the liquid crystal layer can be set to a desired value. Further, as apparent from the equations (26) to (29), the effective voltage applied to the respective liquid crystal layers of the sub-pixels included in each pixel can be changed by appropriately changing the value of the auxiliary capacitance in each dark pixel. The difference can be set to a desired value.
　また、各暗画素における蓄積容量比の値、または、各暗画素における補助容量の値は、表示画像に生じ得る色ずれの現象を低減するように定めることができる。 Also, the value of the storage capacity ratio in each dark pixel or the value of the auxiliary capacity in each dark pixel can be determined so as to reduce the phenomenon of color shift that may occur in the display image.
　以下では、表示画像に生じ得る色ずれの現象を低減するような、各暗画素における蓄積容量比の値についての説明を行う。 Hereinafter, the value of the storage capacity ratio in each dark pixel that reduces the phenomenon of color misregistration that may occur in the display image will be described.
　（正面からの見え方）
　図１２は、比較例に係る液晶表示装置の、正面視角における、階調と三刺激値（Ｘ値、Ｙ値、Ｚ値）との関係（特性）を示す図である。なお、三刺激値については、実施形態１で説明したので、ここでは説明を省略する。 (View from the front)
FIG. 12 is a diagram illustrating a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device according to the comparative example. Since tristimulus values have been described in the first embodiment, description thereof is omitted here.
　ここで、当該比較例に係る液晶表示装置は、ＶＡモードの液晶表示装置であり、本実施形態に係る液晶表示装置１００と同様の画素構造を有しており、液晶表示装置１００と同様に３ＴＦＴ駆動方式によって各画素を駆動する。 Here, the liquid crystal display device according to the comparative example is a VA mode liquid crystal display device, and has the same pixel structure as the liquid crystal display device 100 according to the present embodiment. Each pixel is driven by a driving method.
　また、当該比較例に係る液晶表示装置におけるＲ画素８’、Ｇ画素１０’、および、Ｙｅ画素１４’の暗画素のそれぞれにおける蓄積容量比ＤＲ’（数式（３０）参照）、ＤＧ’（数式（３２）参照）、およびＤＹｅ’（数式（３３）参照）は、
　ＤＲ’＝ＤＧ’＝ＤＹｅ’＝０．２３３
を満たしている。 In addition, in the liquid crystal display device according to the comparative example, the storage capacitance ratio DR ′ (see Expression (30)) and DG ′ (Expression) in each of the dark pixels of the R pixel 8 ′, the G pixel 10 ′, and the Ye pixel 14 ′. (See (32)), and DYe ′ (see Equation (33))
DR ′ = DG ′ = DYe ′ = 0.233
Meet.
　図１２に示すように、正面視角においては、階調とＸ値、Ｙ値、Ｚ値との関係を示すグラフは、いずれも一定のγ（ガンマ）値を有する曲線となっている。したがって、当該比較例に係る液晶表示装置の表示画面を正面から観察した場合は、色ずれの現象は発生しない。 As shown in FIG. 12, at the front viewing angle, the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant γ (gamma) value. Therefore, when the display screen of the liquid crystal display device according to the comparative example is observed from the front, the phenomenon of color misregistration does not occur.
　（斜め方向からの見え方）
　しかし、ＶＡモードの液晶表示装置は、液晶層複屈折率効果を利用しており、液晶層のリタデーションが波長分散を持つため、光の波長によって透過率が変わる。また、液晶層のリタデーションは正面視角よりも斜め視角において見かけ上大きくなるので、斜め視角では透過率変動の光波長依存性が正面視角よりも増加する。この結果、実施形態１のようなマルチ画素駆動（Multi Pixel Drive）方式のみならず、本実施形態のような３ＴＦＴ駆動方式により駆動する液晶表示装置についても、正面から画面を観察した場合とは異なり、斜め方向から画面を観察した場合のγ値（より具体的には、ｌｏｃａｌγの値）は一定ではなくなるため、斜め方向において、色ずれの現象が発生する。また、色ずれの現象は、ＶＡモードの液晶表示装置にのみ生じるものではなく、例えば、ＴＮモードの液晶表示装置においても発生する。 (View from an oblique direction)
However, since the VA mode liquid crystal display device uses the birefringence effect of the liquid crystal layer and the retardation of the liquid crystal layer has wavelength dispersion, the transmittance varies depending on the wavelength of light. In addition, since the retardation of the liquid crystal layer is apparently larger at an oblique viewing angle than at the front viewing angle, the dependence of the transmittance variation on the light wavelength is greater than the front viewing angle at the oblique viewing angle. As a result, not only the multi-pixel drive method as in the first embodiment but also the liquid crystal display device driven by the 3 TFT drive method as in this embodiment differs from the case where the screen is observed from the front. Since the γ value (more specifically, the value of local γ) when the screen is observed from an oblique direction is not constant, a color misregistration phenomenon occurs in the oblique direction. Further, the color shift phenomenon does not occur only in the VA mode liquid crystal display device, but also occurs in, for example, the TN mode liquid crystal display device.
　図１３は、比較例に係る液晶表示装置の、斜め視角（より具体的には極角６０度）における階調－ＸＹＺ値特性を示す図である。 FIG. 13 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device according to the comparative example.
　図１３に示すように、極角６０度においては、中間調において、Ｘ値およびＹ値がほぼ同じ階調（略１１０階調）にて立ち上がっている。すなわち、極角６０度においては、Ｘ値およびＹ値を示すグラフの傾きが、双方とも、略１１０階調にて変化し、略１１０階調以下における傾きよりも、略１１０階調以上略１３０階調以下における傾きの方が大きくなっている。また、Ｘ値を示すグラフおよびＹ値を示すグラフは、それぞれ、１５０階調付近および１３０階調付近から、なだらかな傾きへと転じている。このようなＸ値およびＹ値を示すグラフのプロファイルは、特に略１００階調～略１５０階調の範囲において、Ｘ値およびＹ値のそれぞれについてのγ値が大きく変化していることを示している。 As shown in FIG. 13, at the polar angle of 60 degrees, in the halftone, the X value and the Y value rise with substantially the same gradation (approximately 110 gradations). That is, at the polar angle of 60 degrees, the slopes of the graphs indicating the X value and the Y value both change at approximately 110 gradations, and are approximately 110 gradations or more and approximately 130 than the inclinations at approximately 110 gradations or less. The slope below the gradation is larger. In addition, the graph indicating the X value and the graph indicating the Y value have turned to a gentle slope from the vicinity of the 150th gradation and the vicinity of the 130th gradation, respectively. Such a profile of the graph showing the X value and the Y value shows that the γ value for each of the X value and the Y value varies greatly, particularly in the range of about 100 gradations to about 150 gradations. Yes.
　このように、極角６０度においては、特に中間調において、Ｘ値およびＹ値を示すグラフの曲線が、γ値が一定である理想曲線から大きく外れるものとなるため、色ずれの現象が生じてしまう。また、このような、階調－ＸＹＺ値特性は、極角６０度に限られるものではなく、その他の極角によって規定される斜め視角においても同様である。したがって、比較例に係る液晶表示装置においては、一般に斜め視角において、中間調における色ずれの現象が生じてしまう。 In this way, at the polar angle of 60 degrees, particularly in the halftone, the curve of the graph showing the X value and the Y value deviates greatly from the ideal curve having a constant γ value, so that a color shift phenomenon occurs. End up. Further, such gradation-XYZ value characteristics are not limited to the polar angle of 60 degrees, and the same applies to oblique viewing angles defined by other polar angles. Therefore, in the liquid crystal display device according to the comparative example, a color misregistration phenomenon occurs in a halftone generally at an oblique viewing angle.
　以下では、当該比較例に係る液晶表示装置におけるＸ値およびＹ値のそれぞれについてのγ値（ｌｏｃａｌγの値）の特性を、図１４を参照してより詳しく説明する。 Hereinafter, the characteristics of the γ value (local γ value) for each of the X value and the Y value in the liquid crystal display device according to the comparative example will be described in more detail with reference to FIG.
　図１４は、比較例に係る液晶表示装置の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。ここで、ｌｏｃａｌγとは、γ値の局所的な傾きを示す指標であり、実施形態１において説明した数式（Ａ１）によって定義される。 FIG. 14 is a diagram showing a gradation-local γ characteristic at a polar angle of 60 degrees of the liquid crystal display device according to the comparative example. Here, local γ is an index indicating a local gradient of the γ value, and is defined by the mathematical formula (A1) described in the first embodiment.
　図１４に示すように、略１００階調以下において、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、互いに略等しい。一方、略１００階調において、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、共に急峻な立ち上がりを示している。Ｘ値に関するｌｏｃａｌγは、略１００階調から略１５０階調までの区間において、略１．０増加し、Ｙ値に関するｌｏｃａｌγは、略１００階調から略１３０階調までの区間において、略１．０増加している。また、Ｙ値のｌｏｃａｌγの中間調（３２階調から１９２階調）における標準偏差σは、σ＝０．３７９となっている。 As shown in FIG. 14, the local γ value related to the X value and the local γ value related to the Y value are substantially equal to each other at about 100 gradations or less. On the other hand, in approximately 100 gradations, the local γ value related to the X value and the local γ value related to the Y value both show steep rises. The local γ related to the X value increases by about 1.0 in the interval from about 100 gradations to about 150 gradations, and the local γ related to the Y value is about 1. in the interval from about 100 gradations to about 130 gradations. 0 increase. In addition, the standard deviation σ in the halftone (32 gradations to 192 gradations) of the local γ of the Y value is σ = 0.379.
　色ずれが生じないようにするためには、ｌｏｃａｌγの値は、斜め視野角においても一定であることが望ましいが、当該比較例に係る液晶表示装置においては、図１４から明らかなように、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、特に略１００階調から略１５０階調において、大きく変化している。 In order to prevent color misregistration, the value of local γ is preferably constant even at an oblique viewing angle. However, in the liquid crystal display device according to the comparative example, as apparent from FIG. The value of local γ relating to the value and the value of local γ relating to the Y value vary greatly, particularly from about 100 gradations to about 150 gradations.
　したがって、当該比較例に係る液晶表示装置においては、斜め視角において、中間調における色ずれが発生してしまう。 Therefore, in the liquid crystal display device according to the comparative example, a color shift in halftone occurs at an oblique viewing angle.
　また、実施形態１と同様に、ｌｏｃａｌγの標準偏差σは、色ずれの大きさを示す指標として用いることもできる。これは、標準偏差σが大きいことは、ｌｏｃａｌγの階調毎の変化が大きいことに対応し、標準偏差σが小さいことは、ｌｏｃａｌγの階調毎の変化が小さいこと、すなわち、ｌｏｃａｌγが一定に近いことに対応するためである。したがって、例えば、上記ｌｏｃａｌγの標準偏差σの値がより小さくなるように、各暗画素における蓄積容量比を最適化することができれば、色ずれの現象を低減することができる。 Similarly to the first embodiment, the standard deviation σ of local γ can also be used as an index indicating the magnitude of color shift. This means that a large standard deviation σ corresponds to a large change in local γ for each gradation, and a small standard deviation σ means a small change in local γ for each gradation, that is, local γ is constant. This is to cope with closeness. Therefore, for example, if the storage capacity ratio in each dark pixel can be optimized so that the value of the standard deviation σ of the local γ becomes smaller, the color shift phenomenon can be reduced.
　（実施形態に係る液晶表示装置１００における容量比の最適化）
　以下では、色ずれの現象を低減するために最適化された、本実施形態に係る液晶表示装置１００の表示パネルが備える各暗画素における蓄積容量比について説明する。 (Optimization of the capacitance ratio in the liquid crystal display device 100 according to the embodiment)
Hereinafter, the storage capacity ratio in each dark pixel included in the display panel of the liquid crystal display device 100 according to the present embodiment optimized for reducing the phenomenon of color misregistration will be described.
　本実施形態に係る液晶表示装置１００の表示パネルにおいては、Ｒ画素８’、Ｇ画素１０’、および、Ｙｅ画素１４’の暗画素のそれぞれにおける蓄積容量比ＤＲ’（数式（３０）参照）、ＤＧ’（数式（３２）参照）、およびＤＹｅ’（数式（３３）参照）は、
　ＤＲ’＝ＤＧ’＝０．２３３
　ＤＹｅ’＝０．１
を満たしている。 In the display panel of the liquid crystal display device 100 according to the present embodiment, the storage capacitance ratio DR ′ (see Expression (30)) in each of the dark pixels of the R pixel 8 ′, the G pixel 10 ′, and the Ye pixel 14 ′, DG ′ (see Equation (32)) and DYe ′ (see Equation (33)) are
DR ′ = DG ′ = 0.233
DYe '= 0.1
Meet.
　上記のように、蓄積容量比ＤＹｅ’が、蓄積容量比ＤＲ’および蓄積容量比ＤＧ’に比べて小さいため、Ｙｅ画素１４’の備える各副画素の液晶層に印加される実効電圧の差ΔＶ１２Ｙｅ’は、Ｒ画素８’およびＧ画素１０’のそれぞれ備える各副画素の液晶層に印加される実効電圧の差ΔＶ１２Ｒ’およびΔＶ１２Ｇ’に比べて、小さい。 As described above, since the storage capacity ratio DYe ′ is smaller than the storage capacity ratio DR ′ and the storage capacity ratio DG ′, the difference ΔV12Ye between effective voltages applied to the liquid crystal layers of the sub-pixels included in the Ye pixel 14 ′. 'Is smaller than the difference ΔV12R' and ΔV12G 'in effective voltage applied to the liquid crystal layer of each subpixel included in each of the R pixel 8' and the G pixel 10 '.
　このように、Ｙｅ画素１４’における実効電圧の差ΔＶ１２Ｙｅ’を、Ｒ画素８’およびＧ画素１０’のそれぞれにおける実効電圧の差ΔＶ１２Ｒ’およびΔＶ１２Ｇ’に比べて小さくすることによって、実施形態１と同様に、例えば、以下のような効果を奏する。 As described above, the effective voltage difference ΔV12Ye ′ in the Ye pixel 14 ′ is made smaller than the effective voltage differences ΔV12R ′ and ΔV12G ′ in the R pixel 8 ′ and the G pixel 10 ′, respectively. Similarly, for example, the following effects can be obtained.
　すなわち、Ｒ画素８’、Ｇ画素１０’、および、Ｙｅ画素１４’の表示する画像の輝度に対して、低階調においては、Ｒ画素８’の備える明画素８ａ’、Ｇ画素１０’の備える明画素１０ａ’、および、Ｙｅ画素１４’の備える明画素１４ａ’が主に寄与し、階調が上がるにつれて、Ｙｅ画素１４’の備える暗画素１４ｂ’が寄与し始め、さらに階調が上がるにつれて、Ｒ画素８’の備える暗画素８ｂ’、および、Ｇ画素１０’の備える暗画素１０ｂ’が寄与し始める。 That is, with respect to the brightness of the image displayed by the R pixel 8 ′, the G pixel 10 ′, and the Ye pixel 14 ′, in the low gradation, the bright pixels 8a ′ and G pixels 10 ′ included in the R pixel 8 ′. The bright pixel 10a ′ provided and the bright pixel 14a ′ provided in the Ye pixel 14 ′ mainly contribute, and as the gradation increases, the dark pixel 14b ′ provided in the Ye pixel 14 ′ starts to contribute and the gradation further increases. Accordingly, the dark pixel 8b ′ included in the R pixel 8 ′ and the dark pixel 10b ′ included in the G pixel 10 ′ start to contribute.
　換言すれば、本実施形態に係る液晶表示装置１００においては、赤色、緑色、および、黄色を成分として含む色の輝度が、階調が上がるに従い、少なくとも３段階に分かれて立ち上がる。 In other words, in the liquid crystal display device 100 according to the present embodiment, the luminance of the color including red, green, and yellow as components rises in at least three stages as the gradation increases.
　これは、本実施形態に係る液晶表示装置１００が、赤色、緑色、および、黄色を成分として含む色を表示する場合、画素が副画素に少なくとも３分割されていることと同様の効果を奏することを示している。したがって、本実施形態に係る液晶表示装置１００においては、特にＸ値およびＹ値についてのｌｏｃａｌγを、より一定に近づけることができる。 When the liquid crystal display device 100 according to the present embodiment displays colors including red, green, and yellow as components, the same effect is obtained as when the pixel is divided into at least three subpixels. Is shown. Therefore, in the liquid crystal display device 100 according to the present embodiment, the local γ particularly with respect to the X value and the Y value can be made more constant.
　一方で、ＤＲ’＝ＤＧ’＝ＤＹｅ’に設定されている比較例に係る液晶表示装置においては、Ｙｅ画素１４’における実効電圧の差ΔＶ１２Ｙｅ’が、Ｒ画素８’およびＧ画素１０’のそれぞれにおける実効電圧の差ΔＶ１２Ｒ’およびΔＶ１２Ｇ’に等しい。 On the other hand, in the liquid crystal display device according to the comparative example in which DR ′ = DG ′ = DYe ′, the effective voltage difference ΔV12Ye ′ in the Ye pixel 14 ′ is different between the R pixel 8 ′ and the G pixel 10 ′. Is equal to the difference ΔV12R ′ and ΔV12G ′ in effective voltage at.
　このため、比較例に係る液晶表示装置においては、低階調においては、Ｒ画素８’の備える明画素８ａ’、Ｇ画素１０’の備える明画素１０ａ’、および、Ｙｅ画素１４’の備える明画素１４ａ’が主に寄与し、階調が上がるにつれて、Ｙｅ画素１４’の備える暗画素１４ｂ’、Ｒ画素８’の備える暗画素８ｂ’、および、Ｇ画素１０’の備える暗画素１０ｂ’が一様に寄与し始める。したがって、比較例に係る液晶表示装置においては、赤色、緑色、および、黄色を成分として含む色の輝度が、２段階に分かれて立ち上がるに過ぎない。 Therefore, in the liquid crystal display device according to the comparative example, in the low gradation, the bright pixel 8a ′ included in the R pixel 8 ′, the bright pixel 10a ′ included in the G pixel 10 ′, and the bright pixel included in the Ye pixel 14 ′. As the pixel 14a ′ mainly contributes and the gradation increases, the dark pixel 14b ′ included in the Ye pixel 14 ′, the dark pixel 8b ′ included in the R pixel 8 ′, and the dark pixel 10b ′ included in the G pixel 10 ′ Begin to contribute uniformly. Therefore, in the liquid crystal display device according to the comparative example, the luminance of the color including red, green, and yellow as components only rises in two stages.
　このように、本実施形態に係る液晶表示装置１００は、蓄積容量比ＤＹｅ’を、蓄積容量比ＤＲ’および蓄積容量比ＤＧ’に比べて小さく設定することによって、赤色、緑色、および、黄色を成分として含む色の輝度を、階調が上がるに従い、少なくとも３段階に分かれて立ち上げることができるので、比較例に係る液晶表示装置に比べて、特にＸ値およびＹ値についてのｌｏｃａｌγを、より一定に近づけることができる。したがって、液晶表示装置１００は、斜め視野角における色ずれの現象を効果的に抑制することができる。 As described above, the liquid crystal display device 100 according to the present embodiment sets red, green, and yellow by setting the storage capacity ratio DYe ′ to be smaller than the storage capacity ratio DR ′ and the storage capacity ratio DG ′. Since the luminance of the color included as a component can be raised in at least three stages as the gradation increases, the local γ particularly for the X value and the Y value can be increased more than the liquid crystal display device according to the comparative example. Can be close to constant. Therefore, the liquid crystal display device 100 can effectively suppress the phenomenon of color misregistration at an oblique viewing angle.
　以下では、図１５～図１８を参照して、本実施形態に係る液晶表示装置１００の奏する効果について、より具体的に説明する。 Hereinafter, the effects produced by the liquid crystal display device 100 according to the present embodiment will be described more specifically with reference to FIGS.
　図１５は、本実施形態に係る液晶表示装置１００の、正面視角における、階調と三刺激値（Ｘ値、Ｙ値、Ｚ値）との関係（特性）を示す図である。 FIG. 15 is a diagram showing a relationship (characteristic) between the gradation and the tristimulus values (X value, Y value, Z value) at the front viewing angle of the liquid crystal display device 100 according to the present embodiment.
　図１５に示すように、正面視角においては、階調とＸ値、Ｙ値、Ｚ値との関係を示すグラフは、いずれも一定のγ（ガンマ）値を有する曲線となっている。したがって、本実施形態に係る液晶表示装置１００の表示画面を正面から観察した場合は、色ずれの現象は発生しない。 As shown in FIG. 15, at the front viewing angle, the graph showing the relationship between the gradation and the X value, Y value, and Z value is a curve having a constant γ (gamma) value. Therefore, when the display screen of the liquid crystal display device 100 according to the present embodiment is observed from the front, the phenomenon of color misregistration does not occur.
　図１６は、本実施形態に係る液晶表示装置１００の、斜め視角（より具体的には極角６０度）における階調－ＸＹＺ値特性を示す図である。 FIG. 16 is a diagram showing gradation-XYZ value characteristics at an oblique viewing angle (more specifically, a polar angle of 60 degrees) of the liquid crystal display device 100 according to the present embodiment.
　図１６に示すように、Ｘ値およびＹ値の双方について、略１００階調～略１５０階調の範囲におけるγ値の変化が、比較例に係る液晶表示装置に比べて小さくなっている。このように、本実施形態に係る液晶表示装置１００においては、Ｘ値およびＹ値を示すグラフの曲線が、γ値が一定である理想曲線により近いものとなるため、色ずれの現象が抑制される。 As shown in FIG. 16, for both the X value and the Y value, the change in the γ value in the range of approximately 100 gradations to approximately 150 gradations is smaller than that of the liquid crystal display device according to the comparative example. As described above, in the liquid crystal display device 100 according to the present embodiment, the curve of the graph indicating the X value and the Y value is closer to the ideal curve with a constant γ value, so that the phenomenon of color shift is suppressed. The
　図１７は、本実施形態に係る液晶表示装置１００の、極角６０度における階調―ｌｏｃａｌγ特性を示す図である。 FIG. 17 is a diagram showing the gradation-local γ characteristic at the polar angle of 60 degrees of the liquid crystal display device 100 according to the present embodiment.
　図１７から明らかなように、Ｘ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値は、略２０階調から略２２０階調までの範囲において、略一定の値をとっている。これは、比較例に係る液晶表示装置におけるＸ値に関するｌｏｃａｌγの値、および、Ｙ値に関するｌｏｃａｌγの値が、略１００階調～略１５０階調の範囲において、大きく変化していることと対照的である。 As is clear from FIG. 17, the value of local γ related to the X value and the value of local γ related to the Y value take substantially constant values in a range from about 20 gradations to about 220 gradations. This is in contrast to the fact that the value of local γ relating to the X value and the value of local γ relating to the Y value in the liquid crystal display device according to the comparative example change greatly in the range of approximately 100 gradations to approximately 150 gradations. It is.
　なお、Ｙ値のｌｏｃａｌγの中間調（３２階調から１９２階調）における標準偏差σは、σ＝０．２４２であり、比較例に係る液晶表示装置における標準偏差σ＝０．３７９に比べて小さい。このことからも、斜め視野角におけるＸ値およびＹ値の特性が、正面視野角における特性により近いことが分かる。 Note that the standard deviation σ in the halftone (32 gradations to 192 gradations) of the local γ of the Y value is σ = 0.242, compared with the standard deviation σ = 0.379 in the liquid crystal display device according to the comparative example. small. This also shows that the characteristics of the X value and the Y value at the oblique viewing angle are closer to the characteristics at the front viewing angle.
　以上のように、本実施形態に係る液晶表示装置１００によれば、Ｙｅ画素１４’における実効電圧の差ΔＶ１２Ｙｅ’を、Ｒ画素８’およびＧ画素１０’のそれぞれにおける実効電圧の差ΔＶ１２Ｒ’およびΔＶ１２Ｇ’に比べて小さくすることによって、斜め視野角における色ずれの現象を効果的に抑制することができる。 As described above, according to the liquid crystal display device 100 according to the present embodiment, the effective voltage difference ΔV12Ye ′ in the Ye pixel 14 ′ is changed to the effective voltage difference ΔV12R ′ in the R pixel 8 ′ and the G pixel 10 ′. By making it smaller than ΔV12G ′, the phenomenon of color shift at an oblique viewing angle can be effectively suppressed.
　図１８（ａ）は、本実施形態に係る液晶表示装置１００において、試験的に設定された蓄積容量ＣｄＹｅ’の蓄積容量ＣｄＧ’に対する比（ＣｄＹｅ’／ＣｄＧ’）と、各比に対応するＹ値のｌｏｃａｌγの中間調（３２階調から１９２階調）における標準偏差σとの関係を示す表である。また、図１８（ｂ）は、上記比ＣｄＹｅ’／ＣｄＧ’と、上記標準偏差σとの関係を示すグラフである。 FIG. 18A shows the ratio (CdYe ′ / CdG ′) of the storage capacitor CdYe ′ to the storage capacitor CdG ′ set experimentally and Y corresponding to each ratio in the liquid crystal display device 100 according to the present embodiment. It is a table | surface which shows the relationship with the standard deviation (sigma) in the halftone (32 gradations to 192 gradations) of value local (gamma). FIG. 18B is a graph showing the relationship between the ratio CdYe ′ / CdG ′ and the standard deviation σ.
　図１８（ａ）～（ｂ）から明らかなように、上記標準偏差σは、ＣｄＹｅ’／ＣｄＧ’＝０．４２９付近において最小値をとっている。したがって、ＣｄＹｅ’／ＣｄＧ’＝０．４２９となるように、各蓄積容量を設定することによって、色ずれの現象を最も効果的に抑制することができる。 As is apparent from FIGS. 18A to 18B, the standard deviation σ has a minimum value in the vicinity of CdYe ′ / CdG ′ = 0.429. Therefore, the color misregistration phenomenon can be most effectively suppressed by setting the storage capacitors so that CdYe '/ CdG' = 0.429.
　上述したように、本実施形態に係る液晶表示装置１００においては、ＤＲ’＝ＤＧ’＝０．２３３、および、ＤＹｅ’＝０．１を満たすように、各蓄積容量が設定されているが、これは、ＣｄＹｅ’／ＣｄＧ’＝０．４２９を満たすように各蓄積容量が設定されていることに対応している。 As described above, in the liquid crystal display device 100 according to the present embodiment, each storage capacitor is set so as to satisfy DR ′ = DG ′ = 0.233 and DYe ′ = 0.1. This corresponds to the fact that each storage capacity is set to satisfy CdYe ′ / CdG ′ = 0.429.
　したがって、本実施形態に係る液晶表示装置１００は、各蓄積容量が、色ずれの現象を最も効果的に抑制することができるように、最適化された液晶表示装置であると表現することができる。 Therefore, the liquid crystal display device 100 according to the present embodiment can be expressed as an optimized liquid crystal display device so that each storage capacitor can most effectively suppress the phenomenon of color misregistration. .
　また、図１８（ａ）～（ｂ）から明らかなように、ＣｄＹｅ’／ＣｄＧ’＜１の区間において、上記標準偏差σが、ＣｄＹｅ’／ＣｄＧ’＝１である場合の標準偏差σよりも小さくなっている。これは、ＣｄＹｅ’／ＣｄＧ’＜１を満たすように、各蓄積容量を設定することによって、ＣｄＹｅ’／ＣｄＧ’＝１とした場合に比べて、色ずれの現象を、より効果的に抑制することができることを示している。 Further, as is clear from FIGS. 18A to 18B, in the section of CdYe ′ / CdG ′ <1, the standard deviation σ is more than the standard deviation σ when CdYe ′ / CdG ′ = 1. It is getting smaller. By setting each storage capacity so as to satisfy CdYe ′ / CdG ′ <1, the phenomenon of color misregistration can be suppressed more effectively than when CdYe ′ / CdG ′ = 1. It shows that you can.
　したがって、本実施形態に係る液晶表示装置１００においては、ＣｄＹｅ’／ＣｄＧ’＝０．４２９に限らず、ＣｄＹｅ’／ＣｄＧ’＜１を満たすように各蓄積容量を設定してもよく、そのような場合についても、本実施形態に係る液晶表示装置１００は、色ずれの現象を効果的に抑制することができる。 Therefore, in the liquid crystal display device 100 according to the present embodiment, each storage capacitor may be set so as to satisfy CdYe ′ / CdG ′ <1, without being limited to CdYe ′ / CdG ′ = 0.429. Even in such a case, the liquid crystal display device 100 according to the present embodiment can effectively suppress the phenomenon of color misregistration.
　（実施形態１および実施形態２についての付記事項）
　実施形態１および実施形態２においては、液晶表示装置１および液晶表示装置１００が、赤色、緑色、および青色の３原色の各々を表示する画素と、赤色と緑色との組み合わせによって得られる黄色を表示する画素とを個別に備え、黄色を表示する画素についての実効電圧の差ΔＶ１２Ｙｅ（ΔＶ１２Ｙｅ’）を、赤色を表示する画素および緑色を表示する画素のそれぞれにおける実効電圧の差ΔＶ１２Ｒ（ΔＶ１２Ｒ’）およびΔＶ１２Ｇ（ΔＶ１２Ｇ’）に比べて小さくする構成を例に挙げたが、上記実施形態はこれに限定されるものではない。 (Additional information about Embodiment 1 and Embodiment 2)
In the first embodiment and the second embodiment, the liquid crystal display device 1 and the liquid crystal display device 100 display yellow obtained by a combination of a pixel that displays each of the three primary colors red, green, and blue and red and green. And the effective voltage difference ΔV12Ye (ΔV12Ye ′) for the pixel displaying yellow, and the effective voltage difference ΔV12R (ΔV12R ′) for each of the pixel displaying red and the pixel displaying green. Although a configuration in which the size is smaller than ΔV12G (ΔV12G ′) has been described as an example, the embodiment is not limited thereto.
　例えば、上記実施形態に係る液晶表示装置は、赤色と緑色との組み合わせによって得られる黄色を表示する画素に代えて、赤色と緑色と青色との組み合わせよって得られる白色を表示する画素を備え、当該白色を表示する画素についての実効電圧の差を、赤色を表示する画素、緑色を表示する画素、および、青色を表示する画素のそれぞれにおける実効電圧の差に比べて小さくする構成としてもよい。 For example, the liquid crystal display device according to the embodiment includes a pixel that displays white obtained by a combination of red, green, and blue, instead of a pixel that displays yellow obtained by a combination of red and green, The difference in effective voltage for pixels that display white may be configured to be smaller than the difference in effective voltage among pixels that display red, pixels that display green, and pixels that display blue.
　また、本実施形態に係る液晶表示装置は、赤色、緑色、および青色以外の３原色、例えば、シアン（Ｃ）、マゼンタ（Ｍ）、およびイエロー（Ｙ）の３原色を個別に表示する画素と、シアン、マゼンタ、およびイエローのうち少なくとも２色（例えば、シアンおよびマゼンタ）の組み合わせによって得られる色を表示する画素とを個別に備え、当該少なくとも２色の組み合わせによって得られる色を表示する画素についての実効電圧の差を、当該少なくとも２色をそれぞれ表示する画素（例えば、シアンを表示する画素、および、マゼンタを表示する画素）についての実効電圧の差に比べて小さくする構成としてもよい。 In addition, the liquid crystal display device according to the present embodiment includes three primary colors other than red, green, and blue, for example, pixels that individually display the three primary colors of cyan (C), magenta (M), and yellow (Y). A pixel that individually displays a color obtained by a combination of at least two colors (for example, cyan and magenta) of cyan, magenta, and yellow, and that displays a color obtained by the combination of at least two colors The effective voltage difference may be made smaller than the effective voltage difference for pixels that display at least two colors (for example, pixels that display cyan and pixels that display magenta).
　より一般的には、３原色の各々をＣ１、Ｃ２、およびＣ３と表し、ＣｉとＣｊとの組み合わせによって得られる色をＣｉ＋Ｃｊと表すことにすると、上記実施形態に係る液晶表示装置は、３原色（Ｃ１、Ｃ２、Ｃ３）、および、当該３原色のうち特定の複数の原色を組み合わせることにより得られる特定の混色（Ｃ１＋Ｃ２、Ｃ２＋Ｃ３、Ｃ３＋Ｃ１、または、Ｃ１＋Ｃ２＋Ｃ３）を表示する画素とを個別に備え、前記特定の複数の原色をそれぞれ表示する画素についての実効電圧の差を、前記特定の混色を表示する画素についての実効電圧の差と異ならせる構成であると表現することができる。 More generally, if each of the three primary colors is represented as C1, C2, and C3, and a color obtained by a combination of Ci and Cj is represented as Ci + Cj, the liquid crystal display device according to the above embodiment has three primary colors. (C1, C2, C3) and a pixel for displaying a specific mixed color (C1 + C2, C2 + C3, C3 + C1, or C1 + C2 + C3) obtained by combining a plurality of specific primary colors among the three primary colors, It can be expressed as a configuration in which the difference in effective voltage for the pixels displaying the plurality of specific primary colors is different from the difference in effective voltage for the pixels displaying the specific color mixture.
　上記実施形態に係る液晶表示装置は、このような構成をとることにより、上記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることができるので、斜め視野角における色ずれの現象を抑制することができる。 By adopting such a configuration, the liquid crystal display device according to the embodiment is displayed using a plurality of specific primary colors among the three primary colors and a specific color mixture obtained by combining the specific primary colors. Since the gradation-stimulus value characteristic at the oblique viewing angle for the image to be displayed can be brought close to the gradation-stimulus value characteristic at the front viewing angle, the phenomenon of color shift at the oblique viewing angle can be suppressed.
　（まとめ）
　以上のように、本発明に係る表示パネルは、３原色、および、前記３原色のうち特定の複数の原色を組み合わせることにより得られる特定の混色を個別に表示する複数の画素と、前記複数の画素の各々について、第１の副画素と、第２の副画素と、を備え、前記第１の副画素および前記第２の副画素のそれぞれは、対向電極と、液晶層を介して前記対向電極に対向する副画素電極とによって形成された液晶容量と、を有している表示パネルであって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第１の電位差とは異なる第２の電位差を生じさせる、ことを特徴としている。 (Summary)
As described above, the display panel according to the present invention includes a plurality of pixels that individually display three primary colors and a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors; Each of the pixels includes a first subpixel and a second subpixel, and each of the first subpixel and the second subpixel is opposed to the counter electrode through a liquid crystal layer. A display panel having a liquid crystal capacitor formed by a sub-pixel electrode facing the electrode, the sub-pixel in the first sub-pixel for each of the pixels displaying the specific primary colors A first potential difference between the pixel electrode and the sub-pixel electrode in the second sub-pixel, and the sub-pixel electrode in the first sub-pixel for the pixel displaying the specific color mixture; The second Between the sub-pixel electrodes in the pixel causes a different second potential difference between the first potential difference, it is characterized in that.
　上記のように構成された本発明に係る表示パネルは、前記３原色のうち特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に第１の電位差を生じさせると共に、前記３原色のうち前記特定の複数の原色を組み合わせることにより得られる特定の混色を表示する画素についての、第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第１の電位差とは異なる第２の電位差を生じさせる。 In the display panel according to the present invention configured as described above, the sub-pixel electrode and the second sub-pixel in the first sub-pixel of a pixel that respectively displays a plurality of specific primary colors among the three primary colors. A first sub-pixel for a pixel that generates a first potential difference with the sub-pixel electrode in the pixel and displays a specific mixed color obtained by combining the plurality of specific primary colors among the three primary colors. A second potential difference different from the first potential difference is generated between the sub-pixel electrode in the pixel and the sub-pixel electrode in the second sub-pixel.
　上記のように構成された表示パネルは、前記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての、斜め視野角における急峻な輝度変化を抑制することによって、斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることができるので、斜め視野角における色ずれの現象を効果的に抑制することができる。 The display panel configured as described above has an oblique viewing angle with respect to an image displayed using a plurality of specific primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors. By suppressing the steep luminance change in the image, the gradation-stimulus value characteristic at the oblique viewing angle can be brought close to the gradation-stimulus value characteristic at the front viewing angle, so that the phenomenon of color shift at the oblique viewing angle is effective. Can be suppressed.
　すなわち、上記の構成によれば、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に抑制することができる。 That is, according to the above configuration, it is possible to effectively suppress the phenomenon of color shift caused by a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel.
　また、本発明に係る表示パネルにおいては、前記複数の画素の各々について、前記第１の副画素および前記第２の副画素のそれぞれは、前記副画素電極に接続された補助容量電極と、絶縁層を介して前記補助容量電極に対向する補助容量対向電極とによって形成された少なくとも１つの補助容量と、を更に有しており、当該表示パネルは、前記副画素電極に対して画素電極電圧が印加された後に、前記補助容量対向電極に対して、補助容量電圧を印加することによって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に前記第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第２の電位差を生じさせる、ものであり、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値と、前記特定の混色を表示する画素についての前記補助容量の容量値とは互いに異なっている、ことが好ましい。 In the display panel according to the present invention, for each of the plurality of pixels, each of the first subpixel and the second subpixel is insulated from an auxiliary capacitance electrode connected to the subpixel electrode. At least one auxiliary capacitance formed by an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via a layer, and the display panel has a pixel electrode voltage with respect to the sub-pixel electrode. After being applied, by applying an auxiliary capacitance voltage to the auxiliary capacitance counter electrode, the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode for the pixels that respectively display the specific primary colors A first potential difference is generated between the second subpixel and the subpixel electrode, and a pixel that displays the specific color mixture is displayed in the first subpixel. The second potential difference is generated between the sub-pixel electrode and the sub-pixel electrode in the second sub-pixel, and the auxiliary capacitance of each of the pixels displaying the specific primary colors is displayed. It is preferable that the capacitance value and the capacitance value of the auxiliary capacitance for the pixel displaying the specific color mixture are different from each other.
　上記のように構成された表示パネルは、前記副画素電極に対して画素電極電圧が印加された後に、前記補助容量対向電極に対して、補助容量電圧を印加することによって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に前記第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第２の電位差を生じさせる、マルチ画素駆動（Multi Pixel Drive）方式により各画素の駆動を行うものであり、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値と、前記特定の混色を表示する画素についての前記補助容量の容量値とは互いに異なっているため、前記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての、斜め視野角における急峻な輝度変化を抑制することによって、斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることができる。 In the display panel configured as described above, after a pixel electrode voltage is applied to the sub-pixel electrode, an auxiliary capacitance voltage is applied to the auxiliary capacitance counter electrode, whereby the specific plurality of specific display devices For each of the pixels displaying primary colors, the first potential difference is generated between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel, and the specific color mixture Multi-pixel driving (Multi Pixel) for generating the second potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel. Each pixel is driven by a drive method, and a capacitance value of the auxiliary capacitor for each pixel that displays the specific primary colors and a pixel that displays the specific color mixture. Since the capacity value of the auxiliary capacity is different from each other, an image displayed using a specific plurality of primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors. By suppressing the sharp luminance change at the oblique viewing angle, the gradation-stimulus value characteristic at the oblique viewing angle can be brought close to the gradation-stimulus value characteristic at the front viewing angle.
　したがって、上記の構成によれば、上記表示パネルが上記３原色を個別に表示する画素に加えて、上記３原色以外の色を表示する画素を備え、各画素がマルチ画素駆動方式により駆動される場合について、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に抑制することができる。 Therefore, according to the above configuration, the display panel includes pixels that display colors other than the three primary colors in addition to the pixels that individually display the three primary colors, and each pixel is driven by a multi-pixel driving method. In this case, it is possible to effectively suppress a color shift phenomenon caused by a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel.
　また、前記特定の混色を表示する画素についての前記補助容量の容量値は、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値の０．１倍よりも大きく、かつ、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値よりも小さい、ことが好ましい。 In addition, the capacitance value of the auxiliary capacitance for the pixel that displays the specific mixed color is greater than 0.1 times the capacitance value of the auxiliary capacitance for the pixel that respectively displays the specific plurality of primary colors, and It is preferable that the capacitance value is smaller than the capacitance value of the auxiliary capacitor for each pixel displaying the specific plurality of primary colors.
　発明者は、各画素がマルチ画素駆動方式により駆動される場合の実験データから、前記特定の混色を表示する画素についての前記補助容量の容量値が、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値の０．１倍よりも大きく、かつ、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値よりも小さい場合に、前記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての斜め視野角における階調－刺激値特性が、正面視野角における階調－刺激値特性により近くなることを見出した。したがって、上記の構成によれば、色ずれの現象をより効果的に抑制することができる。 The inventor has found from the experimental data when each pixel is driven by the multi-pixel driving method that the capacitance value of the auxiliary capacitor for the pixel displaying the specific color mixture displays the specific primary colors respectively. A specific value among the three primary colors when the capacitance value is larger than 0.1 times the capacitance value of the auxiliary capacitance and smaller than the capacitance value of the auxiliary capacitance for each of the pixels displaying the specific plurality of primary colors. The gradation-stimulus value characteristic at an oblique viewing angle for an image displayed using a plurality of primary colors and a specific color mixture obtained by combining the specific primary colors is a gradation-stimulus value at a front viewing angle. We found that it is closer to the characteristics. Therefore, according to the above configuration, the phenomenon of color misregistration can be more effectively suppressed.
　また、本発明に係る本発明に係る表示パネルにおいては、前記複数の画素の各々について、前記第２の副画素は、蓄積容量電極と、絶縁層を介して前記蓄積容量電極に対向する蓄積容量対向電極とによって形成された少なくとも１つの蓄積容量と、前記蓄積容量電極に電気的に接続されたソース電極と、前記副画素電極に電気的に接続されたドレイン電極とを備えるトランジスタと、を更に有しており、当該表示パネルは、前記副画素電極に対して画素電極電圧が印加された後に、前記トランジスタの備えるソース電極とドレイン電極とを導通させることによって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に前記第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第２の電位差を生じさせる、ものであり、前記特定の複数の原色をそれぞれ表示する画素についての前記蓄積容量の容量値と、前記特定の混色を表示する画素についての前記蓄積容量の容量値とは互いに異なっている、ことが好ましい。 In the display panel according to the present invention, the second sub-pixel of each of the plurality of pixels includes a storage capacitor electrode and a storage capacitor facing the storage capacitor electrode through an insulating layer. A transistor comprising: at least one storage capacitor formed by a counter electrode; a source electrode electrically connected to the storage capacitor electrode; and a drain electrode electrically connected to the sub-pixel electrode. The display panel includes the specific plurality of primary colors by electrically connecting a source electrode and a drain electrode of the transistor after a pixel electrode voltage is applied to the sub-pixel electrode. For the pixel to be displayed, the first potential difference between the subpixel electrode in the first subpixel and the subpixel electrode in the second subpixel. And generating the second potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel for the pixel displaying the specific color mixture. A capacity value of the storage capacitor for each pixel that displays the specific plurality of primary colors and a capacity value of the storage capacitor for the pixel that displays the specific color mixture are different from each other. It is preferable.
　上記のように構成された表示パネルは、前記副画素電極に対して画素電極電圧が印加された後に、前記トランジスタの備えるソース電極とドレイン電極とを導通させることによって、前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に前記第１の電位差を生じさせると共に、前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第２の電位差を生じさせる、３ＴＦＴ駆動方式に相当する駆動方式により各画素の駆動を行うものであり、前記特定の複数の原色をそれぞれ表示する画素についての前記蓄積容量の容量値と、前記特定の混色を表示する画素についての前記蓄積容量の容量値とは互いに異なっているため、前記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての、斜め視野角における急峻な輝度変化を抑制することによって、斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることができる。 In the display panel configured as described above, after a pixel electrode voltage is applied to the sub-pixel electrode, the source electrode and the drain electrode included in the transistor are electrically connected to each other so that the specific plurality of primary colors can be obtained. For each pixel to be displayed, the first potential difference is generated between the subpixel electrode in the first subpixel and the subpixel electrode in the second subpixel, and the specific color mixture is displayed. A driving method corresponding to a 3-TFT driving method for generating the second potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel. Each pixel is driven by the display, and the capacitance value of the storage capacitor and the specific color mixture for the pixels displaying the specific primary colors are displayed. Since the capacitance values of the storage capacitors of the pixels are different from each other, they are displayed using a plurality of specific primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors. By suppressing a steep luminance change at an oblique viewing angle for an image, the gradation-stimulus value characteristic at the oblique viewing angle can be brought close to the gradation-stimulus value characteristic at the front viewing angle.
　したがって、上記の構成によれば、上記表示パネルが上記３原色を個別に表示する画素に加えて、上記３原色以外の色を表示する画素を備え、各画素が３ＴＦＴ駆動方式に相当する駆動方式により駆動される場合について、各色の画素における副画素の数を増大させることなく、斜め視野角における急峻な輝度変化に起因する色ずれの現象を効果的に抑制することができる。 Therefore, according to the above-described configuration, the display panel includes pixels that display colors other than the three primary colors in addition to the pixels that individually display the three primary colors, and each pixel has a driving system corresponding to the 3TFT driving system. In the case of being driven by the above, it is possible to effectively suppress the phenomenon of color misregistration caused by a steep luminance change at an oblique viewing angle without increasing the number of sub-pixels in each color pixel.
　また、前記特定の混色を表示する画素についての前記蓄積容量の容量値は、前記特定の複数の原色をそれぞれ表示する画素についての前記蓄積容量の容量値よりも小さい、ことが好ましい。 In addition, it is preferable that the capacity value of the storage capacitor for the pixel displaying the specific color mixture is smaller than the capacity value of the storage capacitor for the pixel displaying each of the specific plurality of primary colors.
　発明者は、各画素が３ＴＦＴ駆動方式に相当する駆動方式により駆動される場合の実験データから、前記特定の混色を表示する画素についての前記蓄積容量の容量値は、前記特定の複数の原色をそれぞれ表示する画素についての前記蓄積容量の容量値よりも小さい場合に、前記３原色のうち特定の複数の原色と、当該特定の原色を組み合わせることにより得られる特定の混色とを用いて表示される画像についての斜め視野角における階調－刺激値特性が、正面視野角における階調－刺激値特性により近くなることを見出した。したがって、上記の構成によれば、色ずれの現象をより効果的に抑制することができる。 From the experimental data when each pixel is driven by a driving method corresponding to the 3TFT driving method, the inventor determines that the capacitance value of the storage capacitor for the pixel displaying the specific color mixture is the specific plurality of primary colors. When each of the pixels to be displayed is smaller than the capacity value of the storage capacity, the display is performed using a specific plurality of primary colors among the three primary colors and a specific mixed color obtained by combining the specific primary colors. It has been found that the gradation-stimulus value characteristic at an oblique viewing angle for an image is closer to the gradation-stimulus characteristic at a front viewing angle. Therefore, according to the above configuration, the phenomenon of color misregistration can be more effectively suppressed.
　また、前記特定の複数の原色は、前記３原色のうち特定の２つの原色であり、前記特定の混色は、前記特定の２つの原色を組み合わせることにより得られるものである、ことが好ましい。 Further, it is preferable that the specific primary colors are specific two primary colors among the three primary colors, and the specific mixed color is obtained by combining the specific two primary colors.
　上記の構成によれば、前記３原色のうち特定の２つの原色と、前記特定の２つの原色を組み合わせることにより得られる混色とを用いて表示される画像についての斜め視野角における階調－刺激値特性を、正面視野角における階調－刺激値特性に近づけることができるので、色ずれの現象を効果的に抑制することができる。 According to the above configuration, the gradation-stimulation at an oblique viewing angle for an image displayed using two specific primary colors of the three primary colors and a mixed color obtained by combining the two specific primary colors Since the value characteristic can be brought close to the gradation-stimulus value characteristic at the front viewing angle, the phenomenon of color misregistration can be effectively suppressed.
　また、前記３原色は、赤色、緑色、および青色であり、前記特定の２つの原色は、赤色および緑色であり、前記特定の混色は、黄色である、ことが好ましい。 Further, it is preferable that the three primary colors are red, green, and blue, the specific two primary colors are red and green, and the specific mixed color is yellow.
　上記の構成によれば、赤色、緑色、および青色をそれぞれ表示する画素と、黄色を表示する画素とを備えている多原色型の液晶表示装置において、色ずれの現象を効果的に抑制することができる。 According to the above configuration, in the multi-primary color liquid crystal display device including pixels that respectively display red, green, and blue and pixels that display yellow, the phenomenon of color misregistration can be effectively suppressed. Can do.
　また、上記表示パネルを備えている液晶表示装置も本発明の範疇に含まれる。 Further, a liquid crystal display device provided with the display panel is also included in the scope of the present invention.
　本発明は上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.
　本発明は、液晶を用いて画像を表示する表示パネルに好適に適用することができる。特に、３原色と３原色以外の色との組み合わせによってカラー画像を表示する表示パネルに好適に適用することができる。また、そのような表示パネルを備えた液晶表示装置に好適に適用することができる。 The present invention can be suitably applied to a display panel that displays an image using liquid crystal. In particular, the present invention can be suitably applied to a display panel that displays a color image by a combination of three primary colors and colors other than the three primary colors. Further, it can be suitably applied to a liquid crystal display device including such a display panel.
１，１００　　　　液晶表示装置
２，２’　　　　　ゲートバスライン
４，４’　　　　　ソースバスライン
６，６’　　　　　ＣＳバスライン
８，８’　　　　　Ｒ画素
８ａ，８ａ’　　　Ｒ画素の明画素（第１の副画素）
８ｂ，８ｂ’　　　Ｒ画素の暗画素（第２の副画素）
１０，１０’　　　Ｇ画素
１０ａ，１０ａ’　Ｇ画素の明画素（第１の副画素）
１０ｂ，１０ｂ’　Ｇ画素の暗画素（第２の副画素）
１２，１２’　　　Ｂ画素
１２ａ，１２ａ’　Ｂ画素の明画素（第１の副画素）
１２ｂ，１２ｂ’　Ｂ画素の暗画素（第２の副画素）
１４，１４’　　　Ｙｅ画素
１４ａ，１４ａ’　Ｙｅ画素の明画素（第１の副画素）
１４ｂ，１４ｂ’　Ｙｅ画素の暗画素（第２の副画素）
Ｃｓ１Ｒ　　　　　補助容量
Ｃｓ１Ｇ　　　　　補助容量
Ｃｓ１Ｂ　　　　　補助容量
Ｃｓ１Ｙｅ　　　　補助容量
Ｃｓ２Ｒ　　　　　補助容量
Ｃｓ２Ｇ　　　　　補助容量
Ｃｓ２Ｂ　　　　　補助容量
Ｃｓ２Ｙｅ　　　　補助容量
ＣｄＲ’　　　　蓄積容量
ＣｄＧ’　　　　蓄積容量
ＣｄＢ’　　　　蓄積容量
ＣｄＹｅ’　　　蓄積容量 1,100 Liquid crystal display device 2, 2 'Gate bus line 4, 4' Source bus line 6, 6 'CS bus line 8, 8' R pixel 8a, 8a 'Bright pixel (first subpixel)
Dark pixels (second sub-pixels) of 8b and 8b ′ R pixels
Bright pixels (first sub-pixels) of 10, 10 ′ G pixels 10a, 10a ′ G pixels
Dark pixels (second subpixels) of 10b and 10b ′ G pixels
Bright pixels (first sub-pixels) of the 12 and 12 ′ B pixels 12a and 12a ′ B pixels
Dark pixels (second subpixels) of 12b and 12b ′ B pixels
14, 14 ′ Ye pixels 14a, 14a ′ Ye pixel bright pixels (first sub-pixel)
Dark pixels (second subpixels) of 14b and 14b ′ Ye pixels
Cs1R Auxiliary capacitor Cs1G Auxiliary capacitor Cs1B Auxiliary capacitor Cs1Ye Auxiliary capacitor Cs2R Auxiliary capacitor Cs2G Auxiliary capacitor Cs2B Auxiliary capacitor Cs2Ye Auxiliary capacitor CdR 'Storage capacitor CdG' Storage capacitor CdB 'Storage capacitor CdYe' Storage capacitor

Claims (8)

  1. 　３原色、および、前記３原色のうち特定の複数の原色を組み合わせることにより得られる特定の混色を個別に表示する複数の画素と、
    　前記複数の画素の各々について、第１の副画素と、第２の副画素と、を備え、
    　前記第１の副画素および前記第２の副画素のそれぞれは、
    　対向電極と、液晶層を介して前記対向電極に対向する副画素電極とによって形成された液晶容量と、
    を有している表示パネルであって、
    　前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に第１の電位差を生じさせると共に、
    　前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第１の電位差とは異なる第２の電位差を生じさせる、
    ことを特徴とする表示パネル。     A plurality of pixels individually displaying three primary colors and a specific mixed color obtained by combining a plurality of specific primary colors among the three primary colors;
    Each of the plurality of pixels includes a first subpixel and a second subpixel,
    Each of the first subpixel and the second subpixel is:
    A liquid crystal capacitor formed by a counter electrode and a sub-pixel electrode facing the counter electrode via a liquid crystal layer;
    A display panel having
    Producing a first potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel for each of the pixels displaying the specific plurality of primary colors;
    For the pixel displaying the specific color mixture, a second potential different from the first potential difference is provided between the subpixel electrode in the first subpixel and the subpixel electrode in the second subpixel. Create a potential difference,
    A display panel characterized by that.
  2. 　前記複数の画素の各々について、前記第１の副画素および前記第２の副画素のそれぞれは、
    　前記副画素電極に接続された補助容量電極と、絶縁層を介して前記補助容量電極に対向する補助容量対向電極とによって形成された少なくとも１つの補助容量と、を更に有しており、
    　当該表示パネルは、
    　前記副画素電極に対して画素電極電圧が印加された後に、前記補助容量対向電極に対して、補助容量電圧を印加することによって、
    　前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に前記第１の電位差を生じさせると共に、
    　前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第２の電位差を生じさせる、ものであり、
    　前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値と、前記特定の混色を表示する画素についての前記補助容量の容量値とは互いに異なっている、
    ことを特徴とする請求項１に記載の表示パネル。     For each of the plurality of pixels, each of the first subpixel and the second subpixel is:
    An auxiliary capacitance electrode connected to the subpixel electrode; and at least one auxiliary capacitance formed by an auxiliary capacitance counter electrode facing the auxiliary capacitance electrode via an insulating layer;
    The display panel
    After a pixel electrode voltage is applied to the sub-pixel electrode, an auxiliary capacitance voltage is applied to the auxiliary capacitance counter electrode,
    Causing the first potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel for each of the pixels displaying the plurality of specific primary colors, respectively; ,
    Causing the second potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel for the pixel displaying the specific color mixture; Yes,
    The capacity value of the auxiliary capacity for the pixels that respectively display the specific plurality of primary colors and the capacity value of the auxiliary capacity for the pixels that display the specific color mixture are different from each other.
    The display panel according to claim 1.
  3. 　前記特定の混色を表示する画素についての前記補助容量の容量値は、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値の０．１倍よりも大きく、かつ、前記特定の複数の原色をそれぞれ表示する画素についての前記補助容量の容量値よりも小さい、
    ことを特徴とする請求項２に記載の表示パネル。     The capacitance value of the auxiliary capacitance for the pixel displaying the specific mixed color is larger than 0.1 times the capacitance value of the auxiliary capacitance for the pixel displaying the specific primary colors, respectively, and the specific capacitance Smaller than the capacity value of the auxiliary capacity for each of the pixels displaying the plurality of primary colors,
    The display panel according to claim 2.
  4. 　前記複数の画素の各々について、前記第２の副画素は、
    　蓄積容量電極と、絶縁層を介して前記蓄積容量電極に対向する蓄積容量対向電極とによって形成された少なくとも１つの蓄積容量と、
    　前記蓄積容量電極に電気的に接続されたソース電極と、前記副画素電極に電気的に接続されたドレイン電極とを備えるトランジスタと、
    を更に有しており、
    　当該表示パネルは、
    　前記副画素電極に対して画素電極電圧が印加された後に、前記トランジスタの備えるソース電極とドレイン電極とを導通させることによって、
    　前記特定の複数の原色をそれぞれ表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に前記第１の電位差を生じさせると共に、
    　前記特定の混色を表示する画素についての、前記第１の副画素における前記副画素電極と前記第２の副画素における前記副画素電極との間に、前記第２の電位差を生じさせる、ものであり、
    　前記特定の複数の原色をそれぞれ表示する画素についての前記蓄積容量の容量値と、前記特定の混色を表示する画素についての前記蓄積容量の容量値とは互いに異なっている、
    ことを特徴とする請求項１に記載の表示パネル。     For each of the plurality of pixels, the second subpixel is:
    At least one storage capacitor formed by a storage capacitor electrode and a storage capacitor counter electrode facing the storage capacitor electrode via an insulating layer;
    A transistor comprising a source electrode electrically connected to the storage capacitor electrode and a drain electrode electrically connected to the subpixel electrode;
    In addition,
    The display panel
    After the pixel electrode voltage is applied to the sub-pixel electrode, the source electrode and the drain electrode included in the transistor are made conductive,
    Causing the first potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel for each of the pixels displaying the plurality of specific primary colors, respectively; ,
    Causing the second potential difference between the sub-pixel electrode in the first sub-pixel and the sub-pixel electrode in the second sub-pixel for the pixel displaying the specific color mixture; Yes,
    The capacitance value of the storage capacitor for each pixel that displays the specific plurality of primary colors and the capacitance value of the storage capacitor for the pixel that displays the specific mixed color are different from each other.
    The display panel according to claim 1.
  5. 　前記特定の混色を表示する画素についての前記蓄積容量の容量値は、前記特定の複数の原色をそれぞれ表示する画素についての前記蓄積容量の容量値よりも小さい、
    ことを特徴とする請求項４に記載の表示パネル。     The capacitance value of the storage capacitor for the pixel displaying the specific mixed color is smaller than the capacitance value of the storage capacitor for the pixel displaying the specific plurality of primary colors, respectively.
    The display panel according to claim 4.
  6. 　前記特定の複数の原色は、前記３原色のうち特定の２つの原色であり、前記特定の混色は、前記特定の２つの原色を組み合わせることにより得られるものである、
    ことを特徴とする請求項１から５の何れか１項に記載の表示パネル。     The specific plural primary colors are specific two primary colors of the three primary colors, and the specific mixed color is obtained by combining the specific two primary colors.
    The display panel according to claim 1, wherein the display panel is a display panel.
  7. 　前記３原色は、赤色、緑色、および青色であり、前記特定の２つの原色は、赤色および緑色であり、前記特定の混色は、黄色である、
    ことを特徴とする請求項６に記載の表示パネル。     The three primary colors are red, green, and blue, the two specific primary colors are red and green, and the specific mixed color is yellow.
    The display panel according to claim 6.
  8. 　請求項１から７の何れか１項に記載の表示パネルを備えている、ことを特徴とする液晶表示装置。 A liquid crystal display device comprising the display panel according to any one of claims 1 to 7.
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